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56
Merge Intervals
Medium
<p>Given an array&nbsp;of <code>intervals</code>&nbsp;where <code>intervals[i] = [start<sub>i</sub>, end<sub>i</sub>]</code>, merge all overlapping intervals, and return <em>an array of the non-overlapping intervals that cover all the intervals in the input</em>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,3],[2,6],[8,10],[15,18]] <strong>Output:</strong> [[1,6],[8,10],[15,18]] <strong>Explanation:</strong> Since intervals [1,3] and [2,6] overlap, merge them into [1,6]. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,4],[4,5]] <strong>Output:</strong> [[1,5]] <strong>Explanation:</strong> Intervals [1,4] and [4,5] are considered overlapping. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= intervals.length &lt;= 10<sup>4</sup></code></li> <li><code>intervals[i].length == 2</code></li> <li><code>0 &lt;= start<sub>i</sub> &lt;= end<sub>i</sub> &lt;= 10<sup>4</sup></code></li> </ul>
Array; Sorting
Java
class Solution { public int[][] merge(int[][] intervals) { Arrays.sort(intervals, Comparator.comparingInt(a -> a[0])); int st = intervals[0][0], ed = intervals[0][1]; List<int[]> ans = new ArrayList<>(); for (int i = 1; i < intervals.length; ++i) { int s = intervals[i][0], e = intervals[i][1]; if (ed < s) { ans.add(new int[] {st, ed}); st = s; ed = e; } else { ed = Math.max(ed, e); } } ans.add(new int[] {st, ed}); return ans.toArray(new int[ans.size()][]); } }
56
Merge Intervals
Medium
<p>Given an array&nbsp;of <code>intervals</code>&nbsp;where <code>intervals[i] = [start<sub>i</sub>, end<sub>i</sub>]</code>, merge all overlapping intervals, and return <em>an array of the non-overlapping intervals that cover all the intervals in the input</em>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,3],[2,6],[8,10],[15,18]] <strong>Output:</strong> [[1,6],[8,10],[15,18]] <strong>Explanation:</strong> Since intervals [1,3] and [2,6] overlap, merge them into [1,6]. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,4],[4,5]] <strong>Output:</strong> [[1,5]] <strong>Explanation:</strong> Intervals [1,4] and [4,5] are considered overlapping. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= intervals.length &lt;= 10<sup>4</sup></code></li> <li><code>intervals[i].length == 2</code></li> <li><code>0 &lt;= start<sub>i</sub> &lt;= end<sub>i</sub> &lt;= 10<sup>4</sup></code></li> </ul>
Array; Sorting
JavaScript
/** * @param {number[][]} intervals * @return {number[][]} */ var merge = function (intervals) { intervals.sort((a, b) => a[0] - b[0]); const result = []; const n = intervals.length; let i = 0; while (i < n) { const left = intervals[i][0]; let right = intervals[i][1]; while (true) { i++; if (i < n && right >= intervals[i][0]) { right = Math.max(right, intervals[i][1]); } else { result.push([left, right]); break; } } } return result; };
56
Merge Intervals
Medium
<p>Given an array&nbsp;of <code>intervals</code>&nbsp;where <code>intervals[i] = [start<sub>i</sub>, end<sub>i</sub>]</code>, merge all overlapping intervals, and return <em>an array of the non-overlapping intervals that cover all the intervals in the input</em>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,3],[2,6],[8,10],[15,18]] <strong>Output:</strong> [[1,6],[8,10],[15,18]] <strong>Explanation:</strong> Since intervals [1,3] and [2,6] overlap, merge them into [1,6]. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,4],[4,5]] <strong>Output:</strong> [[1,5]] <strong>Explanation:</strong> Intervals [1,4] and [4,5] are considered overlapping. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= intervals.length &lt;= 10<sup>4</sup></code></li> <li><code>intervals[i].length == 2</code></li> <li><code>0 &lt;= start<sub>i</sub> &lt;= end<sub>i</sub> &lt;= 10<sup>4</sup></code></li> </ul>
Array; Sorting
Kotlin
class Solution { fun merge(intervals: Array<IntArray>): Array<IntArray> { intervals.sortBy { it[0] } val result = mutableListOf<IntArray>() val n = intervals.size var i = 0 while (i < n) { val left = intervals[i][0] var right = intervals[i][1] while (true) { i++ if (i < n && right >= intervals[i][0]) { right = maxOf(right, intervals[i][1]) } else { result.add(intArrayOf(left, right)) break } } } return result.toTypedArray() } }
56
Merge Intervals
Medium
<p>Given an array&nbsp;of <code>intervals</code>&nbsp;where <code>intervals[i] = [start<sub>i</sub>, end<sub>i</sub>]</code>, merge all overlapping intervals, and return <em>an array of the non-overlapping intervals that cover all the intervals in the input</em>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,3],[2,6],[8,10],[15,18]] <strong>Output:</strong> [[1,6],[8,10],[15,18]] <strong>Explanation:</strong> Since intervals [1,3] and [2,6] overlap, merge them into [1,6]. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,4],[4,5]] <strong>Output:</strong> [[1,5]] <strong>Explanation:</strong> Intervals [1,4] and [4,5] are considered overlapping. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= intervals.length &lt;= 10<sup>4</sup></code></li> <li><code>intervals[i].length == 2</code></li> <li><code>0 &lt;= start<sub>i</sub> &lt;= end<sub>i</sub> &lt;= 10<sup>4</sup></code></li> </ul>
Array; Sorting
Python
class Solution: def merge(self, intervals: List[List[int]]) -> List[List[int]]: intervals.sort() ans = [] st, ed = intervals[0] for s, e in intervals[1:]: if ed < s: ans.append([st, ed]) st, ed = s, e else: ed = max(ed, e) ans.append([st, ed]) return ans
56
Merge Intervals
Medium
<p>Given an array&nbsp;of <code>intervals</code>&nbsp;where <code>intervals[i] = [start<sub>i</sub>, end<sub>i</sub>]</code>, merge all overlapping intervals, and return <em>an array of the non-overlapping intervals that cover all the intervals in the input</em>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,3],[2,6],[8,10],[15,18]] <strong>Output:</strong> [[1,6],[8,10],[15,18]] <strong>Explanation:</strong> Since intervals [1,3] and [2,6] overlap, merge them into [1,6]. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,4],[4,5]] <strong>Output:</strong> [[1,5]] <strong>Explanation:</strong> Intervals [1,4] and [4,5] are considered overlapping. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= intervals.length &lt;= 10<sup>4</sup></code></li> <li><code>intervals[i].length == 2</code></li> <li><code>0 &lt;= start<sub>i</sub> &lt;= end<sub>i</sub> &lt;= 10<sup>4</sup></code></li> </ul>
Array; Sorting
Rust
impl Solution { pub fn merge(mut intervals: Vec<Vec<i32>>) -> Vec<Vec<i32>> { intervals.sort_unstable_by(|a, b| a[0].cmp(&b[0])); let n = intervals.len(); let mut res = vec![]; let mut i = 0; while i < n { let l = intervals[i][0]; let mut r = intervals[i][1]; i += 1; while i < n && r >= intervals[i][0] { r = r.max(intervals[i][1]); i += 1; } res.push(vec![l, r]); } res } }
56
Merge Intervals
Medium
<p>Given an array&nbsp;of <code>intervals</code>&nbsp;where <code>intervals[i] = [start<sub>i</sub>, end<sub>i</sub>]</code>, merge all overlapping intervals, and return <em>an array of the non-overlapping intervals that cover all the intervals in the input</em>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,3],[2,6],[8,10],[15,18]] <strong>Output:</strong> [[1,6],[8,10],[15,18]] <strong>Explanation:</strong> Since intervals [1,3] and [2,6] overlap, merge them into [1,6]. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,4],[4,5]] <strong>Output:</strong> [[1,5]] <strong>Explanation:</strong> Intervals [1,4] and [4,5] are considered overlapping. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= intervals.length &lt;= 10<sup>4</sup></code></li> <li><code>intervals[i].length == 2</code></li> <li><code>0 &lt;= start<sub>i</sub> &lt;= end<sub>i</sub> &lt;= 10<sup>4</sup></code></li> </ul>
Array; Sorting
TypeScript
function merge(intervals: number[][]): number[][] { intervals.sort((a, b) => a[0] - b[0]); const ans: number[][] = []; let [st, ed] = intervals[0]; for (const [s, e] of intervals.slice(1)) { if (ed < s) { ans.push([st, ed]); [st, ed] = [s, e]; } else { ed = Math.max(ed, e); } } ans.push([st, ed]); return ans; }
57
Insert Interval
Medium
<p>You are given an array of non-overlapping intervals <code>intervals</code> where <code>intervals[i] = [start<sub>i</sub>, end<sub>i</sub>]</code> represent the start and the end of the <code>i<sup>th</sup></code> interval and <code>intervals</code> is sorted in ascending order by <code>start<sub>i</sub></code>. You are also given an interval <code>newInterval = [start, end]</code> that represents the start and end of another interval.</p> <p>Insert <code>newInterval</code> into <code>intervals</code> such that <code>intervals</code> is still sorted in ascending order by <code>start<sub>i</sub></code> and <code>intervals</code> still does not have any overlapping intervals (merge overlapping intervals if necessary).</p> <p>Return <code>intervals</code><em> after the insertion</em>.</p> <p><strong>Note</strong> that you don&#39;t need to modify <code>intervals</code> in-place. You can make a new array and return it.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,3],[6,9]], newInterval = [2,5] <strong>Output:</strong> [[1,5],[6,9]] </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,2],[3,5],[6,7],[8,10],[12,16]], newInterval = [4,8] <strong>Output:</strong> [[1,2],[3,10],[12,16]] <strong>Explanation:</strong> Because the new interval [4,8] overlaps with [3,5],[6,7],[8,10]. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>0 &lt;= intervals.length &lt;= 10<sup>4</sup></code></li> <li><code>intervals[i].length == 2</code></li> <li><code>0 &lt;= start<sub>i</sub> &lt;= end<sub>i</sub> &lt;= 10<sup>5</sup></code></li> <li><code>intervals</code> is sorted by <code>start<sub>i</sub></code> in <strong>ascending</strong> order.</li> <li><code>newInterval.length == 2</code></li> <li><code>0 &lt;= start &lt;= end &lt;= 10<sup>5</sup></code></li> </ul>
Array
C++
class Solution { public: vector<vector<int>> insert(vector<vector<int>>& intervals, vector<int>& newInterval) { intervals.emplace_back(newInterval); return merge(intervals); } vector<vector<int>> merge(vector<vector<int>>& intervals) { sort(intervals.begin(), intervals.end()); vector<vector<int>> ans; ans.emplace_back(intervals[0]); for (int i = 1; i < intervals.size(); ++i) { if (ans.back()[1] < intervals[i][0]) { ans.emplace_back(intervals[i]); } else { ans.back()[1] = max(ans.back()[1], intervals[i][1]); } } return ans; } };
57
Insert Interval
Medium
<p>You are given an array of non-overlapping intervals <code>intervals</code> where <code>intervals[i] = [start<sub>i</sub>, end<sub>i</sub>]</code> represent the start and the end of the <code>i<sup>th</sup></code> interval and <code>intervals</code> is sorted in ascending order by <code>start<sub>i</sub></code>. You are also given an interval <code>newInterval = [start, end]</code> that represents the start and end of another interval.</p> <p>Insert <code>newInterval</code> into <code>intervals</code> such that <code>intervals</code> is still sorted in ascending order by <code>start<sub>i</sub></code> and <code>intervals</code> still does not have any overlapping intervals (merge overlapping intervals if necessary).</p> <p>Return <code>intervals</code><em> after the insertion</em>.</p> <p><strong>Note</strong> that you don&#39;t need to modify <code>intervals</code> in-place. You can make a new array and return it.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,3],[6,9]], newInterval = [2,5] <strong>Output:</strong> [[1,5],[6,9]] </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,2],[3,5],[6,7],[8,10],[12,16]], newInterval = [4,8] <strong>Output:</strong> [[1,2],[3,10],[12,16]] <strong>Explanation:</strong> Because the new interval [4,8] overlaps with [3,5],[6,7],[8,10]. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>0 &lt;= intervals.length &lt;= 10<sup>4</sup></code></li> <li><code>intervals[i].length == 2</code></li> <li><code>0 &lt;= start<sub>i</sub> &lt;= end<sub>i</sub> &lt;= 10<sup>5</sup></code></li> <li><code>intervals</code> is sorted by <code>start<sub>i</sub></code> in <strong>ascending</strong> order.</li> <li><code>newInterval.length == 2</code></li> <li><code>0 &lt;= start &lt;= end &lt;= 10<sup>5</sup></code></li> </ul>
Array
C#
public class Solution { public int[][] Insert(int[][] intervals, int[] newInterval) { int[][] newIntervals = new int[intervals.Length + 1][]; for (int i = 0; i < intervals.Length; ++i) { newIntervals[i] = intervals[i]; } newIntervals[intervals.Length] = newInterval; return Merge(newIntervals); } public int[][] Merge(int[][] intervals) { intervals = intervals.OrderBy(a => a[0]).ToArray(); var ans = new List<int[]>(); ans.Add(intervals[0]); for (int i = 1; i < intervals.Length; ++i) { if (ans[ans.Count - 1][1] < intervals[i][0]) { ans.Add(intervals[i]); } else { ans[ans.Count - 1][1] = Math.Max(ans[ans.Count - 1][1], intervals[i][1]); } } return ans.ToArray(); } }
57
Insert Interval
Medium
<p>You are given an array of non-overlapping intervals <code>intervals</code> where <code>intervals[i] = [start<sub>i</sub>, end<sub>i</sub>]</code> represent the start and the end of the <code>i<sup>th</sup></code> interval and <code>intervals</code> is sorted in ascending order by <code>start<sub>i</sub></code>. You are also given an interval <code>newInterval = [start, end]</code> that represents the start and end of another interval.</p> <p>Insert <code>newInterval</code> into <code>intervals</code> such that <code>intervals</code> is still sorted in ascending order by <code>start<sub>i</sub></code> and <code>intervals</code> still does not have any overlapping intervals (merge overlapping intervals if necessary).</p> <p>Return <code>intervals</code><em> after the insertion</em>.</p> <p><strong>Note</strong> that you don&#39;t need to modify <code>intervals</code> in-place. You can make a new array and return it.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,3],[6,9]], newInterval = [2,5] <strong>Output:</strong> [[1,5],[6,9]] </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,2],[3,5],[6,7],[8,10],[12,16]], newInterval = [4,8] <strong>Output:</strong> [[1,2],[3,10],[12,16]] <strong>Explanation:</strong> Because the new interval [4,8] overlaps with [3,5],[6,7],[8,10]. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>0 &lt;= intervals.length &lt;= 10<sup>4</sup></code></li> <li><code>intervals[i].length == 2</code></li> <li><code>0 &lt;= start<sub>i</sub> &lt;= end<sub>i</sub> &lt;= 10<sup>5</sup></code></li> <li><code>intervals</code> is sorted by <code>start<sub>i</sub></code> in <strong>ascending</strong> order.</li> <li><code>newInterval.length == 2</code></li> <li><code>0 &lt;= start &lt;= end &lt;= 10<sup>5</sup></code></li> </ul>
Array
Go
func insert(intervals [][]int, newInterval []int) [][]int { merge := func(intervals [][]int) (ans [][]int) { sort.Slice(intervals, func(i, j int) bool { return intervals[i][0] < intervals[j][0] }) ans = append(ans, intervals[0]) for _, e := range intervals[1:] { if ans[len(ans)-1][1] < e[0] { ans = append(ans, e) } else { ans[len(ans)-1][1] = max(ans[len(ans)-1][1], e[1]) } } return } intervals = append(intervals, newInterval) return merge(intervals) }
57
Insert Interval
Medium
<p>You are given an array of non-overlapping intervals <code>intervals</code> where <code>intervals[i] = [start<sub>i</sub>, end<sub>i</sub>]</code> represent the start and the end of the <code>i<sup>th</sup></code> interval and <code>intervals</code> is sorted in ascending order by <code>start<sub>i</sub></code>. You are also given an interval <code>newInterval = [start, end]</code> that represents the start and end of another interval.</p> <p>Insert <code>newInterval</code> into <code>intervals</code> such that <code>intervals</code> is still sorted in ascending order by <code>start<sub>i</sub></code> and <code>intervals</code> still does not have any overlapping intervals (merge overlapping intervals if necessary).</p> <p>Return <code>intervals</code><em> after the insertion</em>.</p> <p><strong>Note</strong> that you don&#39;t need to modify <code>intervals</code> in-place. You can make a new array and return it.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,3],[6,9]], newInterval = [2,5] <strong>Output:</strong> [[1,5],[6,9]] </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,2],[3,5],[6,7],[8,10],[12,16]], newInterval = [4,8] <strong>Output:</strong> [[1,2],[3,10],[12,16]] <strong>Explanation:</strong> Because the new interval [4,8] overlaps with [3,5],[6,7],[8,10]. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>0 &lt;= intervals.length &lt;= 10<sup>4</sup></code></li> <li><code>intervals[i].length == 2</code></li> <li><code>0 &lt;= start<sub>i</sub> &lt;= end<sub>i</sub> &lt;= 10<sup>5</sup></code></li> <li><code>intervals</code> is sorted by <code>start<sub>i</sub></code> in <strong>ascending</strong> order.</li> <li><code>newInterval.length == 2</code></li> <li><code>0 &lt;= start &lt;= end &lt;= 10<sup>5</sup></code></li> </ul>
Array
Java
class Solution { public int[][] insert(int[][] intervals, int[] newInterval) { int[][] newIntervals = new int[intervals.length + 1][2]; for (int i = 0; i < intervals.length; ++i) { newIntervals[i] = intervals[i]; } newIntervals[intervals.length] = newInterval; return merge(newIntervals); } private int[][] merge(int[][] intervals) { Arrays.sort(intervals, (a, b) -> a[0] - b[0]); List<int[]> ans = new ArrayList<>(); ans.add(intervals[0]); for (int i = 1; i < intervals.length; ++i) { int s = intervals[i][0], e = intervals[i][1]; if (ans.get(ans.size() - 1)[1] < s) { ans.add(intervals[i]); } else { ans.get(ans.size() - 1)[1] = Math.max(ans.get(ans.size() - 1)[1], e); } } return ans.toArray(new int[ans.size()][]); } }
57
Insert Interval
Medium
<p>You are given an array of non-overlapping intervals <code>intervals</code> where <code>intervals[i] = [start<sub>i</sub>, end<sub>i</sub>]</code> represent the start and the end of the <code>i<sup>th</sup></code> interval and <code>intervals</code> is sorted in ascending order by <code>start<sub>i</sub></code>. You are also given an interval <code>newInterval = [start, end]</code> that represents the start and end of another interval.</p> <p>Insert <code>newInterval</code> into <code>intervals</code> such that <code>intervals</code> is still sorted in ascending order by <code>start<sub>i</sub></code> and <code>intervals</code> still does not have any overlapping intervals (merge overlapping intervals if necessary).</p> <p>Return <code>intervals</code><em> after the insertion</em>.</p> <p><strong>Note</strong> that you don&#39;t need to modify <code>intervals</code> in-place. You can make a new array and return it.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,3],[6,9]], newInterval = [2,5] <strong>Output:</strong> [[1,5],[6,9]] </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,2],[3,5],[6,7],[8,10],[12,16]], newInterval = [4,8] <strong>Output:</strong> [[1,2],[3,10],[12,16]] <strong>Explanation:</strong> Because the new interval [4,8] overlaps with [3,5],[6,7],[8,10]. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>0 &lt;= intervals.length &lt;= 10<sup>4</sup></code></li> <li><code>intervals[i].length == 2</code></li> <li><code>0 &lt;= start<sub>i</sub> &lt;= end<sub>i</sub> &lt;= 10<sup>5</sup></code></li> <li><code>intervals</code> is sorted by <code>start<sub>i</sub></code> in <strong>ascending</strong> order.</li> <li><code>newInterval.length == 2</code></li> <li><code>0 &lt;= start &lt;= end &lt;= 10<sup>5</sup></code></li> </ul>
Array
Python
class Solution: def insert( self, intervals: List[List[int]], newInterval: List[int] ) -> List[List[int]]: def merge(intervals: List[List[int]]) -> List[List[int]]: intervals.sort() ans = [intervals[0]] for s, e in intervals[1:]: if ans[-1][1] < s: ans.append([s, e]) else: ans[-1][1] = max(ans[-1][1], e) return ans intervals.append(newInterval) return merge(intervals)
57
Insert Interval
Medium
<p>You are given an array of non-overlapping intervals <code>intervals</code> where <code>intervals[i] = [start<sub>i</sub>, end<sub>i</sub>]</code> represent the start and the end of the <code>i<sup>th</sup></code> interval and <code>intervals</code> is sorted in ascending order by <code>start<sub>i</sub></code>. You are also given an interval <code>newInterval = [start, end]</code> that represents the start and end of another interval.</p> <p>Insert <code>newInterval</code> into <code>intervals</code> such that <code>intervals</code> is still sorted in ascending order by <code>start<sub>i</sub></code> and <code>intervals</code> still does not have any overlapping intervals (merge overlapping intervals if necessary).</p> <p>Return <code>intervals</code><em> after the insertion</em>.</p> <p><strong>Note</strong> that you don&#39;t need to modify <code>intervals</code> in-place. You can make a new array and return it.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,3],[6,9]], newInterval = [2,5] <strong>Output:</strong> [[1,5],[6,9]] </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,2],[3,5],[6,7],[8,10],[12,16]], newInterval = [4,8] <strong>Output:</strong> [[1,2],[3,10],[12,16]] <strong>Explanation:</strong> Because the new interval [4,8] overlaps with [3,5],[6,7],[8,10]. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>0 &lt;= intervals.length &lt;= 10<sup>4</sup></code></li> <li><code>intervals[i].length == 2</code></li> <li><code>0 &lt;= start<sub>i</sub> &lt;= end<sub>i</sub> &lt;= 10<sup>5</sup></code></li> <li><code>intervals</code> is sorted by <code>start<sub>i</sub></code> in <strong>ascending</strong> order.</li> <li><code>newInterval.length == 2</code></li> <li><code>0 &lt;= start &lt;= end &lt;= 10<sup>5</sup></code></li> </ul>
Array
Rust
impl Solution { pub fn insert(intervals: Vec<Vec<i32>>, new_interval: Vec<i32>) -> Vec<Vec<i32>> { let mut merged_intervals = intervals.clone(); merged_intervals.push(vec![new_interval[0], new_interval[1]]); // sort by elem[0] merged_intervals.sort_by_key(|elem| elem[0]); // merge interval let mut result = vec![]; for interval in merged_intervals { if result.is_empty() { result.push(interval); continue; } let last_elem = result.last_mut().unwrap(); if interval[0] > last_elem[1] { result.push(interval); } else { last_elem[1] = last_elem[1].max(interval[1]); } } result } }
57
Insert Interval
Medium
<p>You are given an array of non-overlapping intervals <code>intervals</code> where <code>intervals[i] = [start<sub>i</sub>, end<sub>i</sub>]</code> represent the start and the end of the <code>i<sup>th</sup></code> interval and <code>intervals</code> is sorted in ascending order by <code>start<sub>i</sub></code>. You are also given an interval <code>newInterval = [start, end]</code> that represents the start and end of another interval.</p> <p>Insert <code>newInterval</code> into <code>intervals</code> such that <code>intervals</code> is still sorted in ascending order by <code>start<sub>i</sub></code> and <code>intervals</code> still does not have any overlapping intervals (merge overlapping intervals if necessary).</p> <p>Return <code>intervals</code><em> after the insertion</em>.</p> <p><strong>Note</strong> that you don&#39;t need to modify <code>intervals</code> in-place. You can make a new array and return it.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,3],[6,9]], newInterval = [2,5] <strong>Output:</strong> [[1,5],[6,9]] </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> intervals = [[1,2],[3,5],[6,7],[8,10],[12,16]], newInterval = [4,8] <strong>Output:</strong> [[1,2],[3,10],[12,16]] <strong>Explanation:</strong> Because the new interval [4,8] overlaps with [3,5],[6,7],[8,10]. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>0 &lt;= intervals.length &lt;= 10<sup>4</sup></code></li> <li><code>intervals[i].length == 2</code></li> <li><code>0 &lt;= start<sub>i</sub> &lt;= end<sub>i</sub> &lt;= 10<sup>5</sup></code></li> <li><code>intervals</code> is sorted by <code>start<sub>i</sub></code> in <strong>ascending</strong> order.</li> <li><code>newInterval.length == 2</code></li> <li><code>0 &lt;= start &lt;= end &lt;= 10<sup>5</sup></code></li> </ul>
Array
TypeScript
function insert(intervals: number[][], newInterval: number[]): number[][] { const merge = (intervals: number[][]): number[][] => { intervals.sort((a, b) => a[0] - b[0]); const ans: number[][] = [intervals[0]]; for (let i = 1; i < intervals.length; ++i) { if (ans.at(-1)[1] < intervals[i][0]) { ans.push(intervals[i]); } else { ans.at(-1)[1] = Math.max(ans.at(-1)[1], intervals[i][1]); } } return ans; }; intervals.push(newInterval); return merge(intervals); }
58
Length of Last Word
Easy
<p>Given a string <code>s</code> consisting of words and spaces, return <em>the length of the <strong>last</strong> word in the string.</em></p> <p>A <strong>word</strong> is a maximal <span data-keyword="substring-nonempty">substring</span> consisting of non-space characters only.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> s = &quot;Hello World&quot; <strong>Output:</strong> 5 <strong>Explanation:</strong> The last word is &quot;World&quot; with length 5. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> s = &quot; fly me to the moon &quot; <strong>Output:</strong> 4 <strong>Explanation:</strong> The last word is &quot;moon&quot; with length 4. </pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> s = &quot;luffy is still joyboy&quot; <strong>Output:</strong> 6 <strong>Explanation:</strong> The last word is &quot;joyboy&quot; with length 6. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= s.length &lt;= 10<sup>4</sup></code></li> <li><code>s</code> consists of only English letters and spaces <code>&#39; &#39;</code>.</li> <li>There will be at least one word in <code>s</code>.</li> </ul>
String
C++
class Solution { public: int lengthOfLastWord(string s) { int i = s.size() - 1; while (~i && s[i] == ' ') { --i; } int j = i; while (~j && s[j] != ' ') { --j; } return i - j; } };
58
Length of Last Word
Easy
<p>Given a string <code>s</code> consisting of words and spaces, return <em>the length of the <strong>last</strong> word in the string.</em></p> <p>A <strong>word</strong> is a maximal <span data-keyword="substring-nonempty">substring</span> consisting of non-space characters only.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> s = &quot;Hello World&quot; <strong>Output:</strong> 5 <strong>Explanation:</strong> The last word is &quot;World&quot; with length 5. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> s = &quot; fly me to the moon &quot; <strong>Output:</strong> 4 <strong>Explanation:</strong> The last word is &quot;moon&quot; with length 4. </pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> s = &quot;luffy is still joyboy&quot; <strong>Output:</strong> 6 <strong>Explanation:</strong> The last word is &quot;joyboy&quot; with length 6. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= s.length &lt;= 10<sup>4</sup></code></li> <li><code>s</code> consists of only English letters and spaces <code>&#39; &#39;</code>.</li> <li>There will be at least one word in <code>s</code>.</li> </ul>
String
C#
public class Solution { public int LengthOfLastWord(string s) { int i = s.Length - 1; while (i >= 0 && s[i] == ' ') { --i; } int j = i; while (j >= 0 && s[j] != ' ') { --j; } return i - j; } }
58
Length of Last Word
Easy
<p>Given a string <code>s</code> consisting of words and spaces, return <em>the length of the <strong>last</strong> word in the string.</em></p> <p>A <strong>word</strong> is a maximal <span data-keyword="substring-nonempty">substring</span> consisting of non-space characters only.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> s = &quot;Hello World&quot; <strong>Output:</strong> 5 <strong>Explanation:</strong> The last word is &quot;World&quot; with length 5. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> s = &quot; fly me to the moon &quot; <strong>Output:</strong> 4 <strong>Explanation:</strong> The last word is &quot;moon&quot; with length 4. </pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> s = &quot;luffy is still joyboy&quot; <strong>Output:</strong> 6 <strong>Explanation:</strong> The last word is &quot;joyboy&quot; with length 6. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= s.length &lt;= 10<sup>4</sup></code></li> <li><code>s</code> consists of only English letters and spaces <code>&#39; &#39;</code>.</li> <li>There will be at least one word in <code>s</code>.</li> </ul>
String
Go
func lengthOfLastWord(s string) int { i := len(s) - 1 for i >= 0 && s[i] == ' ' { i-- } j := i for j >= 0 && s[j] != ' ' { j-- } return i - j }
58
Length of Last Word
Easy
<p>Given a string <code>s</code> consisting of words and spaces, return <em>the length of the <strong>last</strong> word in the string.</em></p> <p>A <strong>word</strong> is a maximal <span data-keyword="substring-nonempty">substring</span> consisting of non-space characters only.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> s = &quot;Hello World&quot; <strong>Output:</strong> 5 <strong>Explanation:</strong> The last word is &quot;World&quot; with length 5. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> s = &quot; fly me to the moon &quot; <strong>Output:</strong> 4 <strong>Explanation:</strong> The last word is &quot;moon&quot; with length 4. </pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> s = &quot;luffy is still joyboy&quot; <strong>Output:</strong> 6 <strong>Explanation:</strong> The last word is &quot;joyboy&quot; with length 6. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= s.length &lt;= 10<sup>4</sup></code></li> <li><code>s</code> consists of only English letters and spaces <code>&#39; &#39;</code>.</li> <li>There will be at least one word in <code>s</code>.</li> </ul>
String
Java
class Solution { public int lengthOfLastWord(String s) { int i = s.length() - 1; while (i >= 0 && s.charAt(i) == ' ') { --i; } int j = i; while (j >= 0 && s.charAt(j) != ' ') { --j; } return i - j; } }
58
Length of Last Word
Easy
<p>Given a string <code>s</code> consisting of words and spaces, return <em>the length of the <strong>last</strong> word in the string.</em></p> <p>A <strong>word</strong> is a maximal <span data-keyword="substring-nonempty">substring</span> consisting of non-space characters only.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> s = &quot;Hello World&quot; <strong>Output:</strong> 5 <strong>Explanation:</strong> The last word is &quot;World&quot; with length 5. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> s = &quot; fly me to the moon &quot; <strong>Output:</strong> 4 <strong>Explanation:</strong> The last word is &quot;moon&quot; with length 4. </pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> s = &quot;luffy is still joyboy&quot; <strong>Output:</strong> 6 <strong>Explanation:</strong> The last word is &quot;joyboy&quot; with length 6. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= s.length &lt;= 10<sup>4</sup></code></li> <li><code>s</code> consists of only English letters and spaces <code>&#39; &#39;</code>.</li> <li>There will be at least one word in <code>s</code>.</li> </ul>
String
JavaScript
/** * @param {string} s * @return {number} */ var lengthOfLastWord = function (s) { let i = s.length - 1; while (i >= 0 && s[i] === ' ') { --i; } let j = i; while (j >= 0 && s[j] !== ' ') { --j; } return i - j; };
58
Length of Last Word
Easy
<p>Given a string <code>s</code> consisting of words and spaces, return <em>the length of the <strong>last</strong> word in the string.</em></p> <p>A <strong>word</strong> is a maximal <span data-keyword="substring-nonempty">substring</span> consisting of non-space characters only.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> s = &quot;Hello World&quot; <strong>Output:</strong> 5 <strong>Explanation:</strong> The last word is &quot;World&quot; with length 5. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> s = &quot; fly me to the moon &quot; <strong>Output:</strong> 4 <strong>Explanation:</strong> The last word is &quot;moon&quot; with length 4. </pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> s = &quot;luffy is still joyboy&quot; <strong>Output:</strong> 6 <strong>Explanation:</strong> The last word is &quot;joyboy&quot; with length 6. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= s.length &lt;= 10<sup>4</sup></code></li> <li><code>s</code> consists of only English letters and spaces <code>&#39; &#39;</code>.</li> <li>There will be at least one word in <code>s</code>.</li> </ul>
String
PHP
class Solution { /** * @param String $s * @return Integer */ function lengthOfLastWord($s) { $count = 0; while ($s[strlen($s) - 1] == ' ') { $s = substr($s, 0, -1); } while (strlen($s) != 0 && $s[strlen($s) - 1] != ' ') { $count++; $s = substr($s, 0, -1); } return $count; } }
58
Length of Last Word
Easy
<p>Given a string <code>s</code> consisting of words and spaces, return <em>the length of the <strong>last</strong> word in the string.</em></p> <p>A <strong>word</strong> is a maximal <span data-keyword="substring-nonempty">substring</span> consisting of non-space characters only.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> s = &quot;Hello World&quot; <strong>Output:</strong> 5 <strong>Explanation:</strong> The last word is &quot;World&quot; with length 5. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> s = &quot; fly me to the moon &quot; <strong>Output:</strong> 4 <strong>Explanation:</strong> The last word is &quot;moon&quot; with length 4. </pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> s = &quot;luffy is still joyboy&quot; <strong>Output:</strong> 6 <strong>Explanation:</strong> The last word is &quot;joyboy&quot; with length 6. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= s.length &lt;= 10<sup>4</sup></code></li> <li><code>s</code> consists of only English letters and spaces <code>&#39; &#39;</code>.</li> <li>There will be at least one word in <code>s</code>.</li> </ul>
String
Python
class Solution: def lengthOfLastWord(self, s: str) -> int: i = len(s) - 1 while i >= 0 and s[i] == ' ': i -= 1 j = i while j >= 0 and s[j] != ' ': j -= 1 return i - j
58
Length of Last Word
Easy
<p>Given a string <code>s</code> consisting of words and spaces, return <em>the length of the <strong>last</strong> word in the string.</em></p> <p>A <strong>word</strong> is a maximal <span data-keyword="substring-nonempty">substring</span> consisting of non-space characters only.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> s = &quot;Hello World&quot; <strong>Output:</strong> 5 <strong>Explanation:</strong> The last word is &quot;World&quot; with length 5. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> s = &quot; fly me to the moon &quot; <strong>Output:</strong> 4 <strong>Explanation:</strong> The last word is &quot;moon&quot; with length 4. </pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> s = &quot;luffy is still joyboy&quot; <strong>Output:</strong> 6 <strong>Explanation:</strong> The last word is &quot;joyboy&quot; with length 6. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= s.length &lt;= 10<sup>4</sup></code></li> <li><code>s</code> consists of only English letters and spaces <code>&#39; &#39;</code>.</li> <li>There will be at least one word in <code>s</code>.</li> </ul>
String
Rust
impl Solution { pub fn length_of_last_word(s: String) -> i32 { let s = s.trim_end(); let n = s.len(); for (i, c) in s.char_indices().rev() { if c == ' ' { return (n - i - 1) as i32; } } n as i32 } }
58
Length of Last Word
Easy
<p>Given a string <code>s</code> consisting of words and spaces, return <em>the length of the <strong>last</strong> word in the string.</em></p> <p>A <strong>word</strong> is a maximal <span data-keyword="substring-nonempty">substring</span> consisting of non-space characters only.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> s = &quot;Hello World&quot; <strong>Output:</strong> 5 <strong>Explanation:</strong> The last word is &quot;World&quot; with length 5. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> s = &quot; fly me to the moon &quot; <strong>Output:</strong> 4 <strong>Explanation:</strong> The last word is &quot;moon&quot; with length 4. </pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> s = &quot;luffy is still joyboy&quot; <strong>Output:</strong> 6 <strong>Explanation:</strong> The last word is &quot;joyboy&quot; with length 6. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= s.length &lt;= 10<sup>4</sup></code></li> <li><code>s</code> consists of only English letters and spaces <code>&#39; &#39;</code>.</li> <li>There will be at least one word in <code>s</code>.</li> </ul>
String
TypeScript
function lengthOfLastWord(s: string): number { let i = s.length - 1; while (i >= 0 && s[i] === ' ') { --i; } let j = i; while (j >= 0 && s[j] !== ' ') { --j; } return i - j; }
59
Spiral Matrix II
Medium
<p>Given a positive integer <code>n</code>, generate an <code>n x n</code> <code>matrix</code> filled with elements from <code>1</code> to <code>n<sup>2</sup></code> in spiral order.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0059.Spiral%20Matrix%20II/images/spiraln.jpg" style="width: 242px; height: 242px;" /> <pre> <strong>Input:</strong> n = 3 <strong>Output:</strong> [[1,2,3],[8,9,4],[7,6,5]] </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> n = 1 <strong>Output:</strong> [[1]] </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 20</code></li> </ul>
Array; Matrix; Simulation
C++
class Solution { public: vector<vector<int>> generateMatrix(int n) { vector<vector<int>> ans(n, vector<int>(n, 0)); const int dirs[5] = {0, 1, 0, -1, 0}; int i = 0, j = 0, k = 0; for (int v = 1; v <= n * n; ++v) { ans[i][j] = v; int x = i + dirs[k], y = j + dirs[k + 1]; if (x < 0 || x >= n || y < 0 || y >= n || ans[x][y] != 0) { k = (k + 1) % 4; } i += dirs[k]; j += dirs[k + 1]; } return ans; } };
59
Spiral Matrix II
Medium
<p>Given a positive integer <code>n</code>, generate an <code>n x n</code> <code>matrix</code> filled with elements from <code>1</code> to <code>n<sup>2</sup></code> in spiral order.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0059.Spiral%20Matrix%20II/images/spiraln.jpg" style="width: 242px; height: 242px;" /> <pre> <strong>Input:</strong> n = 3 <strong>Output:</strong> [[1,2,3],[8,9,4],[7,6,5]] </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> n = 1 <strong>Output:</strong> [[1]] </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 20</code></li> </ul>
Array; Matrix; Simulation
Go
func generateMatrix(n int) [][]int { ans := make([][]int, n) for i := range ans { ans[i] = make([]int, n) } dirs := [5]int{0, 1, 0, -1, 0} i, j, k := 0, 0, 0 for v := 1; v <= n*n; v++ { ans[i][j] = v x, y := i+dirs[k], j+dirs[k+1] if x < 0 || x >= n || y < 0 || y >= n || ans[x][y] != 0 { k = (k + 1) % 4 } i += dirs[k] j += dirs[k+1] } return ans }
59
Spiral Matrix II
Medium
<p>Given a positive integer <code>n</code>, generate an <code>n x n</code> <code>matrix</code> filled with elements from <code>1</code> to <code>n<sup>2</sup></code> in spiral order.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0059.Spiral%20Matrix%20II/images/spiraln.jpg" style="width: 242px; height: 242px;" /> <pre> <strong>Input:</strong> n = 3 <strong>Output:</strong> [[1,2,3],[8,9,4],[7,6,5]] </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> n = 1 <strong>Output:</strong> [[1]] </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 20</code></li> </ul>
Array; Matrix; Simulation
Java
class Solution { public int[][] generateMatrix(int n) { int[][] ans = new int[n][n]; final int[] dirs = {0, 1, 0, -1, 0}; int i = 0, j = 0, k = 0; for (int v = 1; v <= n * n; ++v) { ans[i][j] = v; int x = i + dirs[k], y = j + dirs[k + 1]; if (x < 0 || x >= n || y < 0 || y >= n || ans[x][y] != 0) { k = (k + 1) % 4; } i += dirs[k]; j += dirs[k + 1]; } return ans; } }
59
Spiral Matrix II
Medium
<p>Given a positive integer <code>n</code>, generate an <code>n x n</code> <code>matrix</code> filled with elements from <code>1</code> to <code>n<sup>2</sup></code> in spiral order.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0059.Spiral%20Matrix%20II/images/spiraln.jpg" style="width: 242px; height: 242px;" /> <pre> <strong>Input:</strong> n = 3 <strong>Output:</strong> [[1,2,3],[8,9,4],[7,6,5]] </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> n = 1 <strong>Output:</strong> [[1]] </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 20</code></li> </ul>
Array; Matrix; Simulation
JavaScript
/** * @param {number} n * @return {number[][]} */ var generateMatrix = function (n) { const ans = Array.from({ length: n }, () => Array(n).fill(0)); const dirs = [0, 1, 0, -1, 0]; let [i, j, k] = [0, 0, 0]; for (let v = 1; v <= n * n; v++) { ans[i][j] = v; const [x, y] = [i + dirs[k], j + dirs[k + 1]]; if (x < 0 || x >= n || y < 0 || y >= n || ans[x][y] !== 0) { k = (k + 1) % 4; } i += dirs[k]; j += dirs[k + 1]; } return ans; };
59
Spiral Matrix II
Medium
<p>Given a positive integer <code>n</code>, generate an <code>n x n</code> <code>matrix</code> filled with elements from <code>1</code> to <code>n<sup>2</sup></code> in spiral order.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0059.Spiral%20Matrix%20II/images/spiraln.jpg" style="width: 242px; height: 242px;" /> <pre> <strong>Input:</strong> n = 3 <strong>Output:</strong> [[1,2,3],[8,9,4],[7,6,5]] </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> n = 1 <strong>Output:</strong> [[1]] </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 20</code></li> </ul>
Array; Matrix; Simulation
Python
class Solution: def generateMatrix(self, n: int) -> List[List[int]]: ans = [[0] * n for _ in range(n)] dirs = (0, 1, 0, -1, 0) i = j = k = 0 for v in range(1, n * n + 1): ans[i][j] = v x, y = i + dirs[k], j + dirs[k + 1] if x < 0 or x >= n or y < 0 or y >= n or ans[x][y]: k = (k + 1) % 4 i, j = i + dirs[k], j + dirs[k + 1] return ans
59
Spiral Matrix II
Medium
<p>Given a positive integer <code>n</code>, generate an <code>n x n</code> <code>matrix</code> filled with elements from <code>1</code> to <code>n<sup>2</sup></code> in spiral order.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0059.Spiral%20Matrix%20II/images/spiraln.jpg" style="width: 242px; height: 242px;" /> <pre> <strong>Input:</strong> n = 3 <strong>Output:</strong> [[1,2,3],[8,9,4],[7,6,5]] </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> n = 1 <strong>Output:</strong> [[1]] </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 20</code></li> </ul>
Array; Matrix; Simulation
Rust
impl Solution { pub fn generate_matrix(n: i32) -> Vec<Vec<i32>> { let mut ans = vec![vec![0; n as usize]; n as usize]; let dirs = [0, 1, 0, -1, 0]; let (mut i, mut j, mut k) = (0, 0, 0); for v in 1..=n * n { ans[i as usize][j as usize] = v; let (x, y) = (i + dirs[k], j + dirs[k + 1]); if x < 0 || x >= n || y < 0 || y >= n || ans[x as usize][y as usize] != 0 { k = (k + 1) % 4; } i += dirs[k]; j += dirs[k + 1]; } ans } }
59
Spiral Matrix II
Medium
<p>Given a positive integer <code>n</code>, generate an <code>n x n</code> <code>matrix</code> filled with elements from <code>1</code> to <code>n<sup>2</sup></code> in spiral order.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0059.Spiral%20Matrix%20II/images/spiraln.jpg" style="width: 242px; height: 242px;" /> <pre> <strong>Input:</strong> n = 3 <strong>Output:</strong> [[1,2,3],[8,9,4],[7,6,5]] </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> n = 1 <strong>Output:</strong> [[1]] </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 20</code></li> </ul>
Array; Matrix; Simulation
TypeScript
function generateMatrix(n: number): number[][] { const ans: number[][] = Array.from({ length: n }, () => Array(n).fill(0)); const dirs = [0, 1, 0, -1, 0]; let [i, j, k] = [0, 0, 0]; for (let v = 1; v <= n * n; v++) { ans[i][j] = v; const [x, y] = [i + dirs[k], j + dirs[k + 1]]; if (x < 0 || x >= n || y < 0 || y >= n || ans[x][y] !== 0) { k = (k + 1) % 4; } i += dirs[k]; j += dirs[k + 1]; } return ans; }
60
Permutation Sequence
Hard
<p>The set <code>[1, 2, 3, ...,&nbsp;n]</code> contains a total of <code>n!</code> unique permutations.</p> <p>By listing and labeling all of the permutations in order, we get the following sequence for <code>n = 3</code>:</p> <ol> <li><code>&quot;123&quot;</code></li> <li><code>&quot;132&quot;</code></li> <li><code>&quot;213&quot;</code></li> <li><code>&quot;231&quot;</code></li> <li><code>&quot;312&quot;</code></li> <li><code>&quot;321&quot;</code></li> </ol> <p>Given <code>n</code> and <code>k</code>, return the <code>k<sup>th</sup></code> permutation sequence.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre><strong>Input:</strong> n = 3, k = 3 <strong>Output:</strong> "213" </pre><p><strong class="example">Example 2:</strong></p> <pre><strong>Input:</strong> n = 4, k = 9 <strong>Output:</strong> "2314" </pre><p><strong class="example">Example 3:</strong></p> <pre><strong>Input:</strong> n = 3, k = 1 <strong>Output:</strong> "123" </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 9</code></li> <li><code>1 &lt;= k &lt;= n!</code></li> </ul>
Recursion; Math
C++
class Solution { public: string getPermutation(int n, int k) { string ans; bitset<10> vis; for (int i = 0; i < n; ++i) { int fact = 1; for (int j = 1; j < n - i; ++j) fact *= j; for (int j = 1; j <= n; ++j) { if (vis[j]) continue; if (k > fact) k -= fact; else { ans += to_string(j); vis[j] = 1; break; } } } return ans; } };
60
Permutation Sequence
Hard
<p>The set <code>[1, 2, 3, ...,&nbsp;n]</code> contains a total of <code>n!</code> unique permutations.</p> <p>By listing and labeling all of the permutations in order, we get the following sequence for <code>n = 3</code>:</p> <ol> <li><code>&quot;123&quot;</code></li> <li><code>&quot;132&quot;</code></li> <li><code>&quot;213&quot;</code></li> <li><code>&quot;231&quot;</code></li> <li><code>&quot;312&quot;</code></li> <li><code>&quot;321&quot;</code></li> </ol> <p>Given <code>n</code> and <code>k</code>, return the <code>k<sup>th</sup></code> permutation sequence.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre><strong>Input:</strong> n = 3, k = 3 <strong>Output:</strong> "213" </pre><p><strong class="example">Example 2:</strong></p> <pre><strong>Input:</strong> n = 4, k = 9 <strong>Output:</strong> "2314" </pre><p><strong class="example">Example 3:</strong></p> <pre><strong>Input:</strong> n = 3, k = 1 <strong>Output:</strong> "123" </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 9</code></li> <li><code>1 &lt;= k &lt;= n!</code></li> </ul>
Recursion; Math
C#
public class Solution { public string GetPermutation(int n, int k) { var ans = new StringBuilder(); int vis = 0; for (int i = 0; i < n; ++i) { int fact = 1; for (int j = 1; j < n - i; ++j) { fact *= j; } for (int j = 1; j <= n; ++j) { if (((vis >> j) & 1) == 0) { if (k > fact) { k -= fact; } else { ans.Append(j); vis |= 1 << j; break; } } } } return ans.ToString(); } }
60
Permutation Sequence
Hard
<p>The set <code>[1, 2, 3, ...,&nbsp;n]</code> contains a total of <code>n!</code> unique permutations.</p> <p>By listing and labeling all of the permutations in order, we get the following sequence for <code>n = 3</code>:</p> <ol> <li><code>&quot;123&quot;</code></li> <li><code>&quot;132&quot;</code></li> <li><code>&quot;213&quot;</code></li> <li><code>&quot;231&quot;</code></li> <li><code>&quot;312&quot;</code></li> <li><code>&quot;321&quot;</code></li> </ol> <p>Given <code>n</code> and <code>k</code>, return the <code>k<sup>th</sup></code> permutation sequence.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre><strong>Input:</strong> n = 3, k = 3 <strong>Output:</strong> "213" </pre><p><strong class="example">Example 2:</strong></p> <pre><strong>Input:</strong> n = 4, k = 9 <strong>Output:</strong> "2314" </pre><p><strong class="example">Example 3:</strong></p> <pre><strong>Input:</strong> n = 3, k = 1 <strong>Output:</strong> "123" </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 9</code></li> <li><code>1 &lt;= k &lt;= n!</code></li> </ul>
Recursion; Math
Go
func getPermutation(n int, k int) string { ans := make([]byte, n) vis := make([]bool, n+1) for i := 0; i < n; i++ { fact := 1 for j := 1; j < n-i; j++ { fact *= j } for j := 1; j <= n; j++ { if !vis[j] { if k > fact { k -= fact } else { ans[i] = byte('0' + j) vis[j] = true break } } } } return string(ans) }
60
Permutation Sequence
Hard
<p>The set <code>[1, 2, 3, ...,&nbsp;n]</code> contains a total of <code>n!</code> unique permutations.</p> <p>By listing and labeling all of the permutations in order, we get the following sequence for <code>n = 3</code>:</p> <ol> <li><code>&quot;123&quot;</code></li> <li><code>&quot;132&quot;</code></li> <li><code>&quot;213&quot;</code></li> <li><code>&quot;231&quot;</code></li> <li><code>&quot;312&quot;</code></li> <li><code>&quot;321&quot;</code></li> </ol> <p>Given <code>n</code> and <code>k</code>, return the <code>k<sup>th</sup></code> permutation sequence.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre><strong>Input:</strong> n = 3, k = 3 <strong>Output:</strong> "213" </pre><p><strong class="example">Example 2:</strong></p> <pre><strong>Input:</strong> n = 4, k = 9 <strong>Output:</strong> "2314" </pre><p><strong class="example">Example 3:</strong></p> <pre><strong>Input:</strong> n = 3, k = 1 <strong>Output:</strong> "123" </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 9</code></li> <li><code>1 &lt;= k &lt;= n!</code></li> </ul>
Recursion; Math
Java
class Solution { public String getPermutation(int n, int k) { StringBuilder ans = new StringBuilder(); boolean[] vis = new boolean[n + 1]; for (int i = 0; i < n; ++i) { int fact = 1; for (int j = 1; j < n - i; ++j) { fact *= j; } for (int j = 1; j <= n; ++j) { if (!vis[j]) { if (k > fact) { k -= fact; } else { ans.append(j); vis[j] = true; break; } } } } return ans.toString(); } }
60
Permutation Sequence
Hard
<p>The set <code>[1, 2, 3, ...,&nbsp;n]</code> contains a total of <code>n!</code> unique permutations.</p> <p>By listing and labeling all of the permutations in order, we get the following sequence for <code>n = 3</code>:</p> <ol> <li><code>&quot;123&quot;</code></li> <li><code>&quot;132&quot;</code></li> <li><code>&quot;213&quot;</code></li> <li><code>&quot;231&quot;</code></li> <li><code>&quot;312&quot;</code></li> <li><code>&quot;321&quot;</code></li> </ol> <p>Given <code>n</code> and <code>k</code>, return the <code>k<sup>th</sup></code> permutation sequence.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre><strong>Input:</strong> n = 3, k = 3 <strong>Output:</strong> "213" </pre><p><strong class="example">Example 2:</strong></p> <pre><strong>Input:</strong> n = 4, k = 9 <strong>Output:</strong> "2314" </pre><p><strong class="example">Example 3:</strong></p> <pre><strong>Input:</strong> n = 3, k = 1 <strong>Output:</strong> "123" </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 9</code></li> <li><code>1 &lt;= k &lt;= n!</code></li> </ul>
Recursion; Math
Python
class Solution: def getPermutation(self, n: int, k: int) -> str: ans = [] vis = [False] * (n + 1) for i in range(n): fact = 1 for j in range(1, n - i): fact *= j for j in range(1, n + 1): if not vis[j]: if k > fact: k -= fact else: ans.append(str(j)) vis[j] = True break return ''.join(ans)
60
Permutation Sequence
Hard
<p>The set <code>[1, 2, 3, ...,&nbsp;n]</code> contains a total of <code>n!</code> unique permutations.</p> <p>By listing and labeling all of the permutations in order, we get the following sequence for <code>n = 3</code>:</p> <ol> <li><code>&quot;123&quot;</code></li> <li><code>&quot;132&quot;</code></li> <li><code>&quot;213&quot;</code></li> <li><code>&quot;231&quot;</code></li> <li><code>&quot;312&quot;</code></li> <li><code>&quot;321&quot;</code></li> </ol> <p>Given <code>n</code> and <code>k</code>, return the <code>k<sup>th</sup></code> permutation sequence.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre><strong>Input:</strong> n = 3, k = 3 <strong>Output:</strong> "213" </pre><p><strong class="example">Example 2:</strong></p> <pre><strong>Input:</strong> n = 4, k = 9 <strong>Output:</strong> "2314" </pre><p><strong class="example">Example 3:</strong></p> <pre><strong>Input:</strong> n = 3, k = 1 <strong>Output:</strong> "123" </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 9</code></li> <li><code>1 &lt;= k &lt;= n!</code></li> </ul>
Recursion; Math
Rust
impl Solution { pub fn get_permutation(n: i32, k: i32) -> String { let mut k = k; let mut ans = String::new(); let mut fact = vec![1; n as usize]; for i in 1..n as usize { fact[i] = fact[i - 1] * (i as i32); } let mut vis = vec![false; n as usize + 1]; for i in 0..n as usize { let cnt = fact[(n as usize) - i - 1]; for j in 1..=n { if vis[j as usize] { continue; } if k > cnt { k -= cnt; } else { ans.push_str(&j.to_string()); vis[j as usize] = true; break; } } } ans } }
60
Permutation Sequence
Hard
<p>The set <code>[1, 2, 3, ...,&nbsp;n]</code> contains a total of <code>n!</code> unique permutations.</p> <p>By listing and labeling all of the permutations in order, we get the following sequence for <code>n = 3</code>:</p> <ol> <li><code>&quot;123&quot;</code></li> <li><code>&quot;132&quot;</code></li> <li><code>&quot;213&quot;</code></li> <li><code>&quot;231&quot;</code></li> <li><code>&quot;312&quot;</code></li> <li><code>&quot;321&quot;</code></li> </ol> <p>Given <code>n</code> and <code>k</code>, return the <code>k<sup>th</sup></code> permutation sequence.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre><strong>Input:</strong> n = 3, k = 3 <strong>Output:</strong> "213" </pre><p><strong class="example">Example 2:</strong></p> <pre><strong>Input:</strong> n = 4, k = 9 <strong>Output:</strong> "2314" </pre><p><strong class="example">Example 3:</strong></p> <pre><strong>Input:</strong> n = 3, k = 1 <strong>Output:</strong> "123" </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 9</code></li> <li><code>1 &lt;= k &lt;= n!</code></li> </ul>
Recursion; Math
TypeScript
function getPermutation(n: number, k: number): string { let ans = ''; const vis = Array.from({ length: n + 1 }, () => false); for (let i = 0; i < n; i++) { let fact = 1; for (let j = 1; j < n - i; j++) { fact *= j; } for (let j = 1; j <= n; j++) { if (!vis[j]) { if (k > fact) { k -= fact; } else { ans += j; vis[j] = true; break; } } } } return ans; }
61
Rotate List
Medium
<p>Given the <code>head</code> of a linked&nbsp;list, rotate the list to the right by <code>k</code> places.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0061.Rotate%20List/images/rotate1.jpg" style="width: 450px; height: 191px;" /> <pre> <strong>Input:</strong> head = [1,2,3,4,5], k = 2 <strong>Output:</strong> [4,5,1,2,3] </pre> <p><strong class="example">Example 2:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0061.Rotate%20List/images/roate2.jpg" style="width: 305px; height: 350px;" /> <pre> <strong>Input:</strong> head = [0,1,2], k = 4 <strong>Output:</strong> [2,0,1] </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li>The number of nodes in the list is in the range <code>[0, 500]</code>.</li> <li><code>-100 &lt;= Node.val &lt;= 100</code></li> <li><code>0 &lt;= k &lt;= 2 * 10<sup>9</sup></code></li> </ul>
Linked List; Two Pointers
C++
/** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode() : val(0), next(nullptr) {} * ListNode(int x) : val(x), next(nullptr) {} * ListNode(int x, ListNode *next) : val(x), next(next) {} * }; */ class Solution { public: ListNode* rotateRight(ListNode* head, int k) { if (!head || !head->next) { return head; } ListNode* cur = head; int n = 0; while (cur) { ++n; cur = cur->next; } k %= n; if (k == 0) { return head; } ListNode* fast = head; ListNode* slow = head; while (k--) { fast = fast->next; } while (fast->next) { fast = fast->next; slow = slow->next; } ListNode* ans = slow->next; slow->next = nullptr; fast->next = head; return ans; } };
61
Rotate List
Medium
<p>Given the <code>head</code> of a linked&nbsp;list, rotate the list to the right by <code>k</code> places.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0061.Rotate%20List/images/rotate1.jpg" style="width: 450px; height: 191px;" /> <pre> <strong>Input:</strong> head = [1,2,3,4,5], k = 2 <strong>Output:</strong> [4,5,1,2,3] </pre> <p><strong class="example">Example 2:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0061.Rotate%20List/images/roate2.jpg" style="width: 305px; height: 350px;" /> <pre> <strong>Input:</strong> head = [0,1,2], k = 4 <strong>Output:</strong> [2,0,1] </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li>The number of nodes in the list is in the range <code>[0, 500]</code>.</li> <li><code>-100 &lt;= Node.val &lt;= 100</code></li> <li><code>0 &lt;= k &lt;= 2 * 10<sup>9</sup></code></li> </ul>
Linked List; Two Pointers
C#
/** * Definition for singly-linked list. * public class ListNode { * public int val; * public ListNode next; * public ListNode(int val=0, ListNode next=null) { * this.val = val; * this.next = next; * } * } */ public class Solution { public ListNode RotateRight(ListNode head, int k) { if (head == null || head.next == null) { return head; } var cur = head; int n = 0; while (cur != null) { cur = cur.next; ++n; } k %= n; if (k == 0) { return head; } var fast = head; var slow = head; while (k-- > 0) { fast = fast.next; } while (fast.next != null) { fast = fast.next; slow = slow.next; } var ans = slow.next; slow.next = null; fast.next = head; return ans; } }
61
Rotate List
Medium
<p>Given the <code>head</code> of a linked&nbsp;list, rotate the list to the right by <code>k</code> places.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0061.Rotate%20List/images/rotate1.jpg" style="width: 450px; height: 191px;" /> <pre> <strong>Input:</strong> head = [1,2,3,4,5], k = 2 <strong>Output:</strong> [4,5,1,2,3] </pre> <p><strong class="example">Example 2:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0061.Rotate%20List/images/roate2.jpg" style="width: 305px; height: 350px;" /> <pre> <strong>Input:</strong> head = [0,1,2], k = 4 <strong>Output:</strong> [2,0,1] </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li>The number of nodes in the list is in the range <code>[0, 500]</code>.</li> <li><code>-100 &lt;= Node.val &lt;= 100</code></li> <li><code>0 &lt;= k &lt;= 2 * 10<sup>9</sup></code></li> </ul>
Linked List; Two Pointers
Go
/** * Definition for singly-linked list. * type ListNode struct { * Val int * Next *ListNode * } */ func rotateRight(head *ListNode, k int) *ListNode { if head == nil || head.Next == nil { return head } cur := head n := 0 for cur != nil { cur = cur.Next n++ } k %= n if k == 0 { return head } fast, slow := head, head for i := 0; i < k; i++ { fast = fast.Next } for fast.Next != nil { fast = fast.Next slow = slow.Next } ans := slow.Next slow.Next = nil fast.Next = head return ans }
61
Rotate List
Medium
<p>Given the <code>head</code> of a linked&nbsp;list, rotate the list to the right by <code>k</code> places.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0061.Rotate%20List/images/rotate1.jpg" style="width: 450px; height: 191px;" /> <pre> <strong>Input:</strong> head = [1,2,3,4,5], k = 2 <strong>Output:</strong> [4,5,1,2,3] </pre> <p><strong class="example">Example 2:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0061.Rotate%20List/images/roate2.jpg" style="width: 305px; height: 350px;" /> <pre> <strong>Input:</strong> head = [0,1,2], k = 4 <strong>Output:</strong> [2,0,1] </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li>The number of nodes in the list is in the range <code>[0, 500]</code>.</li> <li><code>-100 &lt;= Node.val &lt;= 100</code></li> <li><code>0 &lt;= k &lt;= 2 * 10<sup>9</sup></code></li> </ul>
Linked List; Two Pointers
Java
/** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode() {} * ListNode(int val) { this.val = val; } * ListNode(int val, ListNode next) { this.val = val; this.next = next; } * } */ class Solution { public ListNode rotateRight(ListNode head, int k) { if (head == null || head.next == null) { return head; } ListNode cur = head; int n = 0; for (; cur != null; cur = cur.next) { n++; } k %= n; if (k == 0) { return head; } ListNode fast = head; ListNode slow = head; while (k-- > 0) { fast = fast.next; } while (fast.next != null) { fast = fast.next; slow = slow.next; } ListNode ans = slow.next; slow.next = null; fast.next = head; return ans; } }
61
Rotate List
Medium
<p>Given the <code>head</code> of a linked&nbsp;list, rotate the list to the right by <code>k</code> places.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0061.Rotate%20List/images/rotate1.jpg" style="width: 450px; height: 191px;" /> <pre> <strong>Input:</strong> head = [1,2,3,4,5], k = 2 <strong>Output:</strong> [4,5,1,2,3] </pre> <p><strong class="example">Example 2:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0061.Rotate%20List/images/roate2.jpg" style="width: 305px; height: 350px;" /> <pre> <strong>Input:</strong> head = [0,1,2], k = 4 <strong>Output:</strong> [2,0,1] </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li>The number of nodes in the list is in the range <code>[0, 500]</code>.</li> <li><code>-100 &lt;= Node.val &lt;= 100</code></li> <li><code>0 &lt;= k &lt;= 2 * 10<sup>9</sup></code></li> </ul>
Linked List; Two Pointers
Python
# Definition for singly-linked list. # class ListNode: # def __init__(self, val=0, next=None): # self.val = val # self.next = next class Solution: def rotateRight(self, head: Optional[ListNode], k: int) -> Optional[ListNode]: if head is None or head.next is None: return head cur, n = head, 0 while cur: n += 1 cur = cur.next k %= n if k == 0: return head fast = slow = head for _ in range(k): fast = fast.next while fast.next: fast, slow = fast.next, slow.next ans = slow.next slow.next = None fast.next = head return ans
61
Rotate List
Medium
<p>Given the <code>head</code> of a linked&nbsp;list, rotate the list to the right by <code>k</code> places.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0061.Rotate%20List/images/rotate1.jpg" style="width: 450px; height: 191px;" /> <pre> <strong>Input:</strong> head = [1,2,3,4,5], k = 2 <strong>Output:</strong> [4,5,1,2,3] </pre> <p><strong class="example">Example 2:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0061.Rotate%20List/images/roate2.jpg" style="width: 305px; height: 350px;" /> <pre> <strong>Input:</strong> head = [0,1,2], k = 4 <strong>Output:</strong> [2,0,1] </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li>The number of nodes in the list is in the range <code>[0, 500]</code>.</li> <li><code>-100 &lt;= Node.val &lt;= 100</code></li> <li><code>0 &lt;= k &lt;= 2 * 10<sup>9</sup></code></li> </ul>
Linked List; Two Pointers
Rust
// Definition for singly-linked list. // #[derive(PartialEq, Eq, Clone, Debug)] // pub struct ListNode { // pub val: i32, // pub next: Option<Box<ListNode>> // } // // impl ListNode { // #[inline] // fn new(val: i32) -> Self { // ListNode { // next: None, // val // } // } // } impl Solution { pub fn rotate_right(mut head: Option<Box<ListNode>>, mut k: i32) -> Option<Box<ListNode>> { if head.is_none() || k == 0 { return head; } let n = { let mut cur = &head; let mut res = 0; while cur.is_some() { cur = &cur.as_ref().unwrap().next; res += 1; } res }; k = k % n; if k == 0 { return head; } let mut cur = &mut head; for _ in 0..n - k - 1 { cur = &mut cur.as_mut().unwrap().next; } let mut res = cur.as_mut().unwrap().next.take(); cur = &mut res; while cur.is_some() { cur = &mut cur.as_mut().unwrap().next; } *cur = head.take(); res } }
61
Rotate List
Medium
<p>Given the <code>head</code> of a linked&nbsp;list, rotate the list to the right by <code>k</code> places.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0061.Rotate%20List/images/rotate1.jpg" style="width: 450px; height: 191px;" /> <pre> <strong>Input:</strong> head = [1,2,3,4,5], k = 2 <strong>Output:</strong> [4,5,1,2,3] </pre> <p><strong class="example">Example 2:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0061.Rotate%20List/images/roate2.jpg" style="width: 305px; height: 350px;" /> <pre> <strong>Input:</strong> head = [0,1,2], k = 4 <strong>Output:</strong> [2,0,1] </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li>The number of nodes in the list is in the range <code>[0, 500]</code>.</li> <li><code>-100 &lt;= Node.val &lt;= 100</code></li> <li><code>0 &lt;= k &lt;= 2 * 10<sup>9</sup></code></li> </ul>
Linked List; Two Pointers
TypeScript
/** * Definition for singly-linked list. * class ListNode { * val: number * next: ListNode | null * constructor(val?: number, next?: ListNode | null) { * this.val = (val===undefined ? 0 : val) * this.next = (next===undefined ? null : next) * } * } */ function rotateRight(head: ListNode | null, k: number): ListNode | null { if (!head || !head.next) { return head; } let cur = head; let n = 0; while (cur) { cur = cur.next; ++n; } k %= n; if (k === 0) { return head; } let fast = head; let slow = head; while (k--) { fast = fast.next; } while (fast.next) { fast = fast.next; slow = slow.next; } const ans = slow.next; slow.next = null; fast.next = head; return ans; }
62
Unique Paths
Medium
<p>There is a robot on an <code>m x n</code> grid. The robot is initially located at the <strong>top-left corner</strong> (i.e., <code>grid[0][0]</code>). The robot tries to move to the <strong>bottom-right corner</strong> (i.e., <code>grid[m - 1][n - 1]</code>). The robot can only move either down or right at any point in time.</p> <p>Given the two integers <code>m</code> and <code>n</code>, return <em>the number of possible unique paths that the robot can take to reach the bottom-right corner</em>.</p> <p>The test cases are generated so that the answer will be less than or equal to <code>2 * 10<sup>9</sup></code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0062.Unique%20Paths/images/robot_maze.png" style="width: 400px; height: 183px;" /> <pre> <strong>Input:</strong> m = 3, n = 7 <strong>Output:</strong> 28 </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> m = 3, n = 2 <strong>Output:</strong> 3 <strong>Explanation:</strong> From the top-left corner, there are a total of 3 ways to reach the bottom-right corner: 1. Right -&gt; Down -&gt; Down 2. Down -&gt; Down -&gt; Right 3. Down -&gt; Right -&gt; Down </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= m, n &lt;= 100</code></li> </ul>
Math; Dynamic Programming; Combinatorics
C++
class Solution { public: int uniquePaths(int m, int n) { vector<vector<int>> f(m, vector<int>(n)); f[0][0] = 1; for (int i = 0; i < m; ++i) { for (int j = 0; j < n; ++j) { if (i) { f[i][j] += f[i - 1][j]; } if (j) { f[i][j] += f[i][j - 1]; } } } return f[m - 1][n - 1]; } };
62
Unique Paths
Medium
<p>There is a robot on an <code>m x n</code> grid. The robot is initially located at the <strong>top-left corner</strong> (i.e., <code>grid[0][0]</code>). The robot tries to move to the <strong>bottom-right corner</strong> (i.e., <code>grid[m - 1][n - 1]</code>). The robot can only move either down or right at any point in time.</p> <p>Given the two integers <code>m</code> and <code>n</code>, return <em>the number of possible unique paths that the robot can take to reach the bottom-right corner</em>.</p> <p>The test cases are generated so that the answer will be less than or equal to <code>2 * 10<sup>9</sup></code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0062.Unique%20Paths/images/robot_maze.png" style="width: 400px; height: 183px;" /> <pre> <strong>Input:</strong> m = 3, n = 7 <strong>Output:</strong> 28 </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> m = 3, n = 2 <strong>Output:</strong> 3 <strong>Explanation:</strong> From the top-left corner, there are a total of 3 ways to reach the bottom-right corner: 1. Right -&gt; Down -&gt; Down 2. Down -&gt; Down -&gt; Right 3. Down -&gt; Right -&gt; Down </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= m, n &lt;= 100</code></li> </ul>
Math; Dynamic Programming; Combinatorics
Go
func uniquePaths(m int, n int) int { f := make([][]int, m) for i := range f { f[i] = make([]int, n) } f[0][0] = 1 for i := 0; i < m; i++ { for j := 0; j < n; j++ { if i > 0 { f[i][j] += f[i-1][j] } if j > 0 { f[i][j] += f[i][j-1] } } } return f[m-1][n-1] }
62
Unique Paths
Medium
<p>There is a robot on an <code>m x n</code> grid. The robot is initially located at the <strong>top-left corner</strong> (i.e., <code>grid[0][0]</code>). The robot tries to move to the <strong>bottom-right corner</strong> (i.e., <code>grid[m - 1][n - 1]</code>). The robot can only move either down or right at any point in time.</p> <p>Given the two integers <code>m</code> and <code>n</code>, return <em>the number of possible unique paths that the robot can take to reach the bottom-right corner</em>.</p> <p>The test cases are generated so that the answer will be less than or equal to <code>2 * 10<sup>9</sup></code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0062.Unique%20Paths/images/robot_maze.png" style="width: 400px; height: 183px;" /> <pre> <strong>Input:</strong> m = 3, n = 7 <strong>Output:</strong> 28 </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> m = 3, n = 2 <strong>Output:</strong> 3 <strong>Explanation:</strong> From the top-left corner, there are a total of 3 ways to reach the bottom-right corner: 1. Right -&gt; Down -&gt; Down 2. Down -&gt; Down -&gt; Right 3. Down -&gt; Right -&gt; Down </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= m, n &lt;= 100</code></li> </ul>
Math; Dynamic Programming; Combinatorics
Java
class Solution { public int uniquePaths(int m, int n) { var f = new int[m][n]; f[0][0] = 1; for (int i = 0; i < m; ++i) { for (int j = 0; j < n; ++j) { if (i > 0) { f[i][j] += f[i - 1][j]; } if (j > 0) { f[i][j] += f[i][j - 1]; } } } return f[m - 1][n - 1]; } }
62
Unique Paths
Medium
<p>There is a robot on an <code>m x n</code> grid. The robot is initially located at the <strong>top-left corner</strong> (i.e., <code>grid[0][0]</code>). The robot tries to move to the <strong>bottom-right corner</strong> (i.e., <code>grid[m - 1][n - 1]</code>). The robot can only move either down or right at any point in time.</p> <p>Given the two integers <code>m</code> and <code>n</code>, return <em>the number of possible unique paths that the robot can take to reach the bottom-right corner</em>.</p> <p>The test cases are generated so that the answer will be less than or equal to <code>2 * 10<sup>9</sup></code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0062.Unique%20Paths/images/robot_maze.png" style="width: 400px; height: 183px;" /> <pre> <strong>Input:</strong> m = 3, n = 7 <strong>Output:</strong> 28 </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> m = 3, n = 2 <strong>Output:</strong> 3 <strong>Explanation:</strong> From the top-left corner, there are a total of 3 ways to reach the bottom-right corner: 1. Right -&gt; Down -&gt; Down 2. Down -&gt; Down -&gt; Right 3. Down -&gt; Right -&gt; Down </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= m, n &lt;= 100</code></li> </ul>
Math; Dynamic Programming; Combinatorics
JavaScript
/** * @param {number} m * @param {number} n * @return {number} */ var uniquePaths = function (m, n) { const f = Array(m) .fill(0) .map(() => Array(n).fill(0)); f[0][0] = 1; for (let i = 0; i < m; ++i) { for (let j = 0; j < n; ++j) { if (i > 0) { f[i][j] += f[i - 1][j]; } if (j > 0) { f[i][j] += f[i][j - 1]; } } } return f[m - 1][n - 1]; };
62
Unique Paths
Medium
<p>There is a robot on an <code>m x n</code> grid. The robot is initially located at the <strong>top-left corner</strong> (i.e., <code>grid[0][0]</code>). The robot tries to move to the <strong>bottom-right corner</strong> (i.e., <code>grid[m - 1][n - 1]</code>). The robot can only move either down or right at any point in time.</p> <p>Given the two integers <code>m</code> and <code>n</code>, return <em>the number of possible unique paths that the robot can take to reach the bottom-right corner</em>.</p> <p>The test cases are generated so that the answer will be less than or equal to <code>2 * 10<sup>9</sup></code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0062.Unique%20Paths/images/robot_maze.png" style="width: 400px; height: 183px;" /> <pre> <strong>Input:</strong> m = 3, n = 7 <strong>Output:</strong> 28 </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> m = 3, n = 2 <strong>Output:</strong> 3 <strong>Explanation:</strong> From the top-left corner, there are a total of 3 ways to reach the bottom-right corner: 1. Right -&gt; Down -&gt; Down 2. Down -&gt; Down -&gt; Right 3. Down -&gt; Right -&gt; Down </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= m, n &lt;= 100</code></li> </ul>
Math; Dynamic Programming; Combinatorics
Python
class Solution: def uniquePaths(self, m: int, n: int) -> int: f = [[0] * n for _ in range(m)] f[0][0] = 1 for i in range(m): for j in range(n): if i: f[i][j] += f[i - 1][j] if j: f[i][j] += f[i][j - 1] return f[-1][-1]
62
Unique Paths
Medium
<p>There is a robot on an <code>m x n</code> grid. The robot is initially located at the <strong>top-left corner</strong> (i.e., <code>grid[0][0]</code>). The robot tries to move to the <strong>bottom-right corner</strong> (i.e., <code>grid[m - 1][n - 1]</code>). The robot can only move either down or right at any point in time.</p> <p>Given the two integers <code>m</code> and <code>n</code>, return <em>the number of possible unique paths that the robot can take to reach the bottom-right corner</em>.</p> <p>The test cases are generated so that the answer will be less than or equal to <code>2 * 10<sup>9</sup></code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0062.Unique%20Paths/images/robot_maze.png" style="width: 400px; height: 183px;" /> <pre> <strong>Input:</strong> m = 3, n = 7 <strong>Output:</strong> 28 </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> m = 3, n = 2 <strong>Output:</strong> 3 <strong>Explanation:</strong> From the top-left corner, there are a total of 3 ways to reach the bottom-right corner: 1. Right -&gt; Down -&gt; Down 2. Down -&gt; Down -&gt; Right 3. Down -&gt; Right -&gt; Down </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= m, n &lt;= 100</code></li> </ul>
Math; Dynamic Programming; Combinatorics
Rust
impl Solution { pub fn unique_paths(m: i32, n: i32) -> i32 { let (m, n) = (m as usize, n as usize); let mut f = vec![1; n]; for i in 1..m { for j in 1..n { f[j] += f[j - 1]; } } f[n - 1] } }
62
Unique Paths
Medium
<p>There is a robot on an <code>m x n</code> grid. The robot is initially located at the <strong>top-left corner</strong> (i.e., <code>grid[0][0]</code>). The robot tries to move to the <strong>bottom-right corner</strong> (i.e., <code>grid[m - 1][n - 1]</code>). The robot can only move either down or right at any point in time.</p> <p>Given the two integers <code>m</code> and <code>n</code>, return <em>the number of possible unique paths that the robot can take to reach the bottom-right corner</em>.</p> <p>The test cases are generated so that the answer will be less than or equal to <code>2 * 10<sup>9</sup></code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0062.Unique%20Paths/images/robot_maze.png" style="width: 400px; height: 183px;" /> <pre> <strong>Input:</strong> m = 3, n = 7 <strong>Output:</strong> 28 </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> m = 3, n = 2 <strong>Output:</strong> 3 <strong>Explanation:</strong> From the top-left corner, there are a total of 3 ways to reach the bottom-right corner: 1. Right -&gt; Down -&gt; Down 2. Down -&gt; Down -&gt; Right 3. Down -&gt; Right -&gt; Down </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= m, n &lt;= 100</code></li> </ul>
Math; Dynamic Programming; Combinatorics
TypeScript
function uniquePaths(m: number, n: number): number { const f: number[][] = Array(m) .fill(0) .map(() => Array(n).fill(0)); f[0][0] = 1; for (let i = 0; i < m; ++i) { for (let j = 0; j < n; ++j) { if (i > 0) { f[i][j] += f[i - 1][j]; } if (j > 0) { f[i][j] += f[i][j - 1]; } } } return f[m - 1][n - 1]; }
63
Unique Paths II
Medium
<p>You are given an <code>m x n</code> integer array <code>grid</code>. There is a robot initially located at the <b>top-left corner</b> (i.e., <code>grid[0][0]</code>). The robot tries to move to the <strong>bottom-right corner</strong> (i.e., <code>grid[m - 1][n - 1]</code>). The robot can only move either down or right at any point in time.</p> <p>An obstacle and space are marked as <code>1</code> or <code>0</code> respectively in <code>grid</code>. A path that the robot takes cannot include <strong>any</strong> square that is an obstacle.</p> <p>Return <em>the number of possible unique paths that the robot can take to reach the bottom-right corner</em>.</p> <p>The testcases are generated so that the answer will be less than or equal to <code>2 * 10<sup>9</sup></code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0063.Unique%20Paths%20II/images/robot1.jpg" style="width: 242px; height: 242px;" /> <pre> <strong>Input:</strong> obstacleGrid = [[0,0,0],[0,1,0],[0,0,0]] <strong>Output:</strong> 2 <strong>Explanation:</strong> There is one obstacle in the middle of the 3x3 grid above. There are two ways to reach the bottom-right corner: 1. Right -&gt; Right -&gt; Down -&gt; Down 2. Down -&gt; Down -&gt; Right -&gt; Right </pre> <p><strong class="example">Example 2:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0063.Unique%20Paths%20II/images/robot2.jpg" style="width: 162px; height: 162px;" /> <pre> <strong>Input:</strong> obstacleGrid = [[0,1],[0,0]] <strong>Output:</strong> 1 </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>m == obstacleGrid.length</code></li> <li><code>n == obstacleGrid[i].length</code></li> <li><code>1 &lt;= m, n &lt;= 100</code></li> <li><code>obstacleGrid[i][j]</code> is <code>0</code> or <code>1</code>.</li> </ul>
Array; Dynamic Programming; Matrix
C++
class Solution { public: int uniquePathsWithObstacles(vector<vector<int>>& obstacleGrid) { int m = obstacleGrid.size(), n = obstacleGrid[0].size(); vector<vector<int>> f(m, vector<int>(n, -1)); auto dfs = [&](this auto&& dfs, int i, int j) { if (i >= m || j >= n || obstacleGrid[i][j]) { return 0; } if (i == m - 1 && j == n - 1) { return 1; } if (f[i][j] == -1) { f[i][j] = dfs(i + 1, j) + dfs(i, j + 1); } return f[i][j]; }; return dfs(0, 0); } };
63
Unique Paths II
Medium
<p>You are given an <code>m x n</code> integer array <code>grid</code>. There is a robot initially located at the <b>top-left corner</b> (i.e., <code>grid[0][0]</code>). The robot tries to move to the <strong>bottom-right corner</strong> (i.e., <code>grid[m - 1][n - 1]</code>). The robot can only move either down or right at any point in time.</p> <p>An obstacle and space are marked as <code>1</code> or <code>0</code> respectively in <code>grid</code>. A path that the robot takes cannot include <strong>any</strong> square that is an obstacle.</p> <p>Return <em>the number of possible unique paths that the robot can take to reach the bottom-right corner</em>.</p> <p>The testcases are generated so that the answer will be less than or equal to <code>2 * 10<sup>9</sup></code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0063.Unique%20Paths%20II/images/robot1.jpg" style="width: 242px; height: 242px;" /> <pre> <strong>Input:</strong> obstacleGrid = [[0,0,0],[0,1,0],[0,0,0]] <strong>Output:</strong> 2 <strong>Explanation:</strong> There is one obstacle in the middle of the 3x3 grid above. There are two ways to reach the bottom-right corner: 1. Right -&gt; Right -&gt; Down -&gt; Down 2. Down -&gt; Down -&gt; Right -&gt; Right </pre> <p><strong class="example">Example 2:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0063.Unique%20Paths%20II/images/robot2.jpg" style="width: 162px; height: 162px;" /> <pre> <strong>Input:</strong> obstacleGrid = [[0,1],[0,0]] <strong>Output:</strong> 1 </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>m == obstacleGrid.length</code></li> <li><code>n == obstacleGrid[i].length</code></li> <li><code>1 &lt;= m, n &lt;= 100</code></li> <li><code>obstacleGrid[i][j]</code> is <code>0</code> or <code>1</code>.</li> </ul>
Array; Dynamic Programming; Matrix
Go
func uniquePathsWithObstacles(obstacleGrid [][]int) int { m, n := len(obstacleGrid), len(obstacleGrid[0]) f := make([][]int, m) for i := range f { f[i] = make([]int, n) for j := range f[i] { f[i][j] = -1 } } var dfs func(i, j int) int dfs = func(i, j int) int { if i >= m || j >= n || obstacleGrid[i][j] == 1 { return 0 } if i == m-1 && j == n-1 { return 1 } if f[i][j] == -1 { f[i][j] = dfs(i+1, j) + dfs(i, j+1) } return f[i][j] } return dfs(0, 0) }
63
Unique Paths II
Medium
<p>You are given an <code>m x n</code> integer array <code>grid</code>. There is a robot initially located at the <b>top-left corner</b> (i.e., <code>grid[0][0]</code>). The robot tries to move to the <strong>bottom-right corner</strong> (i.e., <code>grid[m - 1][n - 1]</code>). The robot can only move either down or right at any point in time.</p> <p>An obstacle and space are marked as <code>1</code> or <code>0</code> respectively in <code>grid</code>. A path that the robot takes cannot include <strong>any</strong> square that is an obstacle.</p> <p>Return <em>the number of possible unique paths that the robot can take to reach the bottom-right corner</em>.</p> <p>The testcases are generated so that the answer will be less than or equal to <code>2 * 10<sup>9</sup></code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0063.Unique%20Paths%20II/images/robot1.jpg" style="width: 242px; height: 242px;" /> <pre> <strong>Input:</strong> obstacleGrid = [[0,0,0],[0,1,0],[0,0,0]] <strong>Output:</strong> 2 <strong>Explanation:</strong> There is one obstacle in the middle of the 3x3 grid above. There are two ways to reach the bottom-right corner: 1. Right -&gt; Right -&gt; Down -&gt; Down 2. Down -&gt; Down -&gt; Right -&gt; Right </pre> <p><strong class="example">Example 2:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0063.Unique%20Paths%20II/images/robot2.jpg" style="width: 162px; height: 162px;" /> <pre> <strong>Input:</strong> obstacleGrid = [[0,1],[0,0]] <strong>Output:</strong> 1 </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>m == obstacleGrid.length</code></li> <li><code>n == obstacleGrid[i].length</code></li> <li><code>1 &lt;= m, n &lt;= 100</code></li> <li><code>obstacleGrid[i][j]</code> is <code>0</code> or <code>1</code>.</li> </ul>
Array; Dynamic Programming; Matrix
Java
class Solution { private Integer[][] f; private int[][] obstacleGrid; private int m; private int n; public int uniquePathsWithObstacles(int[][] obstacleGrid) { m = obstacleGrid.length; n = obstacleGrid[0].length; this.obstacleGrid = obstacleGrid; f = new Integer[m][n]; return dfs(0, 0); } private int dfs(int i, int j) { if (i >= m || j >= n || obstacleGrid[i][j] == 1) { return 0; } if (i == m - 1 && j == n - 1) { return 1; } if (f[i][j] == null) { f[i][j] = dfs(i + 1, j) + dfs(i, j + 1); } return f[i][j]; } }
63
Unique Paths II
Medium
<p>You are given an <code>m x n</code> integer array <code>grid</code>. There is a robot initially located at the <b>top-left corner</b> (i.e., <code>grid[0][0]</code>). The robot tries to move to the <strong>bottom-right corner</strong> (i.e., <code>grid[m - 1][n - 1]</code>). The robot can only move either down or right at any point in time.</p> <p>An obstacle and space are marked as <code>1</code> or <code>0</code> respectively in <code>grid</code>. A path that the robot takes cannot include <strong>any</strong> square that is an obstacle.</p> <p>Return <em>the number of possible unique paths that the robot can take to reach the bottom-right corner</em>.</p> <p>The testcases are generated so that the answer will be less than or equal to <code>2 * 10<sup>9</sup></code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0063.Unique%20Paths%20II/images/robot1.jpg" style="width: 242px; height: 242px;" /> <pre> <strong>Input:</strong> obstacleGrid = [[0,0,0],[0,1,0],[0,0,0]] <strong>Output:</strong> 2 <strong>Explanation:</strong> There is one obstacle in the middle of the 3x3 grid above. There are two ways to reach the bottom-right corner: 1. Right -&gt; Right -&gt; Down -&gt; Down 2. Down -&gt; Down -&gt; Right -&gt; Right </pre> <p><strong class="example">Example 2:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0063.Unique%20Paths%20II/images/robot2.jpg" style="width: 162px; height: 162px;" /> <pre> <strong>Input:</strong> obstacleGrid = [[0,1],[0,0]] <strong>Output:</strong> 1 </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>m == obstacleGrid.length</code></li> <li><code>n == obstacleGrid[i].length</code></li> <li><code>1 &lt;= m, n &lt;= 100</code></li> <li><code>obstacleGrid[i][j]</code> is <code>0</code> or <code>1</code>.</li> </ul>
Array; Dynamic Programming; Matrix
JavaScript
/** * @param {number[][]} obstacleGrid * @return {number} */ var uniquePathsWithObstacles = function (obstacleGrid) { const m = obstacleGrid.length; const n = obstacleGrid[0].length; const f = Array.from({ length: m }, () => Array(n).fill(-1)); const dfs = (i, j) => { if (i >= m || j >= n || obstacleGrid[i][j] === 1) { return 0; } if (i === m - 1 && j === n - 1) { return 1; } if (f[i][j] === -1) { f[i][j] = dfs(i + 1, j) + dfs(i, j + 1); } return f[i][j]; }; return dfs(0, 0); };
63
Unique Paths II
Medium
<p>You are given an <code>m x n</code> integer array <code>grid</code>. There is a robot initially located at the <b>top-left corner</b> (i.e., <code>grid[0][0]</code>). The robot tries to move to the <strong>bottom-right corner</strong> (i.e., <code>grid[m - 1][n - 1]</code>). The robot can only move either down or right at any point in time.</p> <p>An obstacle and space are marked as <code>1</code> or <code>0</code> respectively in <code>grid</code>. A path that the robot takes cannot include <strong>any</strong> square that is an obstacle.</p> <p>Return <em>the number of possible unique paths that the robot can take to reach the bottom-right corner</em>.</p> <p>The testcases are generated so that the answer will be less than or equal to <code>2 * 10<sup>9</sup></code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0063.Unique%20Paths%20II/images/robot1.jpg" style="width: 242px; height: 242px;" /> <pre> <strong>Input:</strong> obstacleGrid = [[0,0,0],[0,1,0],[0,0,0]] <strong>Output:</strong> 2 <strong>Explanation:</strong> There is one obstacle in the middle of the 3x3 grid above. There are two ways to reach the bottom-right corner: 1. Right -&gt; Right -&gt; Down -&gt; Down 2. Down -&gt; Down -&gt; Right -&gt; Right </pre> <p><strong class="example">Example 2:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0063.Unique%20Paths%20II/images/robot2.jpg" style="width: 162px; height: 162px;" /> <pre> <strong>Input:</strong> obstacleGrid = [[0,1],[0,0]] <strong>Output:</strong> 1 </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>m == obstacleGrid.length</code></li> <li><code>n == obstacleGrid[i].length</code></li> <li><code>1 &lt;= m, n &lt;= 100</code></li> <li><code>obstacleGrid[i][j]</code> is <code>0</code> or <code>1</code>.</li> </ul>
Array; Dynamic Programming; Matrix
Python
class Solution: def uniquePathsWithObstacles(self, obstacleGrid: List[List[int]]) -> int: @cache def dfs(i: int, j: int) -> int: if i >= m or j >= n or obstacleGrid[i][j]: return 0 if i == m - 1 and j == n - 1: return 1 return dfs(i + 1, j) + dfs(i, j + 1) m, n = len(obstacleGrid), len(obstacleGrid[0]) return dfs(0, 0)
63
Unique Paths II
Medium
<p>You are given an <code>m x n</code> integer array <code>grid</code>. There is a robot initially located at the <b>top-left corner</b> (i.e., <code>grid[0][0]</code>). The robot tries to move to the <strong>bottom-right corner</strong> (i.e., <code>grid[m - 1][n - 1]</code>). The robot can only move either down or right at any point in time.</p> <p>An obstacle and space are marked as <code>1</code> or <code>0</code> respectively in <code>grid</code>. A path that the robot takes cannot include <strong>any</strong> square that is an obstacle.</p> <p>Return <em>the number of possible unique paths that the robot can take to reach the bottom-right corner</em>.</p> <p>The testcases are generated so that the answer will be less than or equal to <code>2 * 10<sup>9</sup></code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0063.Unique%20Paths%20II/images/robot1.jpg" style="width: 242px; height: 242px;" /> <pre> <strong>Input:</strong> obstacleGrid = [[0,0,0],[0,1,0],[0,0,0]] <strong>Output:</strong> 2 <strong>Explanation:</strong> There is one obstacle in the middle of the 3x3 grid above. There are two ways to reach the bottom-right corner: 1. Right -&gt; Right -&gt; Down -&gt; Down 2. Down -&gt; Down -&gt; Right -&gt; Right </pre> <p><strong class="example">Example 2:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0063.Unique%20Paths%20II/images/robot2.jpg" style="width: 162px; height: 162px;" /> <pre> <strong>Input:</strong> obstacleGrid = [[0,1],[0,0]] <strong>Output:</strong> 1 </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>m == obstacleGrid.length</code></li> <li><code>n == obstacleGrid[i].length</code></li> <li><code>1 &lt;= m, n &lt;= 100</code></li> <li><code>obstacleGrid[i][j]</code> is <code>0</code> or <code>1</code>.</li> </ul>
Array; Dynamic Programming; Matrix
Rust
impl Solution { pub fn unique_paths_with_obstacles(obstacle_grid: Vec<Vec<i32>>) -> i32 { let m = obstacle_grid.len(); let n = obstacle_grid[0].len(); let mut f = vec![vec![-1; n]; m]; Self::dfs(0, 0, &obstacle_grid, &mut f) } fn dfs(i: usize, j: usize, obstacle_grid: &Vec<Vec<i32>>, f: &mut Vec<Vec<i32>>) -> i32 { let m = obstacle_grid.len(); let n = obstacle_grid[0].len(); if i >= m || j >= n || obstacle_grid[i][j] == 1 { return 0; } if i == m - 1 && j == n - 1 { return 1; } if f[i][j] != -1 { return f[i][j]; } let down = Self::dfs(i + 1, j, obstacle_grid, f); let right = Self::dfs(i, j + 1, obstacle_grid, f); f[i][j] = down + right; f[i][j] } }
63
Unique Paths II
Medium
<p>You are given an <code>m x n</code> integer array <code>grid</code>. There is a robot initially located at the <b>top-left corner</b> (i.e., <code>grid[0][0]</code>). The robot tries to move to the <strong>bottom-right corner</strong> (i.e., <code>grid[m - 1][n - 1]</code>). The robot can only move either down or right at any point in time.</p> <p>An obstacle and space are marked as <code>1</code> or <code>0</code> respectively in <code>grid</code>. A path that the robot takes cannot include <strong>any</strong> square that is an obstacle.</p> <p>Return <em>the number of possible unique paths that the robot can take to reach the bottom-right corner</em>.</p> <p>The testcases are generated so that the answer will be less than or equal to <code>2 * 10<sup>9</sup></code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0063.Unique%20Paths%20II/images/robot1.jpg" style="width: 242px; height: 242px;" /> <pre> <strong>Input:</strong> obstacleGrid = [[0,0,0],[0,1,0],[0,0,0]] <strong>Output:</strong> 2 <strong>Explanation:</strong> There is one obstacle in the middle of the 3x3 grid above. There are two ways to reach the bottom-right corner: 1. Right -&gt; Right -&gt; Down -&gt; Down 2. Down -&gt; Down -&gt; Right -&gt; Right </pre> <p><strong class="example">Example 2:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0063.Unique%20Paths%20II/images/robot2.jpg" style="width: 162px; height: 162px;" /> <pre> <strong>Input:</strong> obstacleGrid = [[0,1],[0,0]] <strong>Output:</strong> 1 </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>m == obstacleGrid.length</code></li> <li><code>n == obstacleGrid[i].length</code></li> <li><code>1 &lt;= m, n &lt;= 100</code></li> <li><code>obstacleGrid[i][j]</code> is <code>0</code> or <code>1</code>.</li> </ul>
Array; Dynamic Programming; Matrix
TypeScript
function uniquePathsWithObstacles(obstacleGrid: number[][]): number { const m = obstacleGrid.length; const n = obstacleGrid[0].length; const f: number[][] = Array.from({ length: m }, () => Array(n).fill(-1)); const dfs = (i: number, j: number): number => { if (i >= m || j >= n || obstacleGrid[i][j] === 1) { return 0; } if (i === m - 1 && j === n - 1) { return 1; } if (f[i][j] === -1) { f[i][j] = dfs(i + 1, j) + dfs(i, j + 1); } return f[i][j]; }; return dfs(0, 0); }
64
Minimum Path Sum
Medium
<p>Given a <code>m x n</code> <code>grid</code> filled with non-negative numbers, find a path from top left to bottom right, which minimizes the sum of all numbers along its path.</p> <p><strong>Note:</strong> You can only move either down or right at any point in time.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0064.Minimum%20Path%20Sum/images/minpath.jpg" style="width: 242px; height: 242px;" /> <pre> <strong>Input:</strong> grid = [[1,3,1],[1,5,1],[4,2,1]] <strong>Output:</strong> 7 <strong>Explanation:</strong> Because the path 1 &rarr; 3 &rarr; 1 &rarr; 1 &rarr; 1 minimizes the sum. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> grid = [[1,2,3],[4,5,6]] <strong>Output:</strong> 12 </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>m == grid.length</code></li> <li><code>n == grid[i].length</code></li> <li><code>1 &lt;= m, n &lt;= 200</code></li> <li><code>0 &lt;= grid[i][j] &lt;= 200</code></li> </ul>
Array; Dynamic Programming; Matrix
C++
class Solution { public: int minPathSum(vector<vector<int>>& grid) { int m = grid.size(), n = grid[0].size(); int f[m][n]; f[0][0] = grid[0][0]; for (int i = 1; i < m; ++i) { f[i][0] = f[i - 1][0] + grid[i][0]; } for (int j = 1; j < n; ++j) { f[0][j] = f[0][j - 1] + grid[0][j]; } for (int i = 1; i < m; ++i) { for (int j = 1; j < n; ++j) { f[i][j] = min(f[i - 1][j], f[i][j - 1]) + grid[i][j]; } } return f[m - 1][n - 1]; } };
64
Minimum Path Sum
Medium
<p>Given a <code>m x n</code> <code>grid</code> filled with non-negative numbers, find a path from top left to bottom right, which minimizes the sum of all numbers along its path.</p> <p><strong>Note:</strong> You can only move either down or right at any point in time.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0064.Minimum%20Path%20Sum/images/minpath.jpg" style="width: 242px; height: 242px;" /> <pre> <strong>Input:</strong> grid = [[1,3,1],[1,5,1],[4,2,1]] <strong>Output:</strong> 7 <strong>Explanation:</strong> Because the path 1 &rarr; 3 &rarr; 1 &rarr; 1 &rarr; 1 minimizes the sum. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> grid = [[1,2,3],[4,5,6]] <strong>Output:</strong> 12 </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>m == grid.length</code></li> <li><code>n == grid[i].length</code></li> <li><code>1 &lt;= m, n &lt;= 200</code></li> <li><code>0 &lt;= grid[i][j] &lt;= 200</code></li> </ul>
Array; Dynamic Programming; Matrix
C#
public class Solution { public int MinPathSum(int[][] grid) { int m = grid.Length, n = grid[0].Length; int[,] f = new int[m, n]; f[0, 0] = grid[0][0]; for (int i = 1; i < m; ++i) { f[i, 0] = f[i - 1, 0] + grid[i][0]; } for (int j = 1; j < n; ++j) { f[0, j] = f[0, j - 1] + grid[0][j]; } for (int i = 1; i < m; ++i) { for (int j = 1; j < n; ++j) { f[i, j] = Math.Min(f[i - 1, j], f[i, j - 1]) + grid[i][j]; } } return f[m - 1, n - 1]; } }
64
Minimum Path Sum
Medium
<p>Given a <code>m x n</code> <code>grid</code> filled with non-negative numbers, find a path from top left to bottom right, which minimizes the sum of all numbers along its path.</p> <p><strong>Note:</strong> You can only move either down or right at any point in time.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0064.Minimum%20Path%20Sum/images/minpath.jpg" style="width: 242px; height: 242px;" /> <pre> <strong>Input:</strong> grid = [[1,3,1],[1,5,1],[4,2,1]] <strong>Output:</strong> 7 <strong>Explanation:</strong> Because the path 1 &rarr; 3 &rarr; 1 &rarr; 1 &rarr; 1 minimizes the sum. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> grid = [[1,2,3],[4,5,6]] <strong>Output:</strong> 12 </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>m == grid.length</code></li> <li><code>n == grid[i].length</code></li> <li><code>1 &lt;= m, n &lt;= 200</code></li> <li><code>0 &lt;= grid[i][j] &lt;= 200</code></li> </ul>
Array; Dynamic Programming; Matrix
Go
func minPathSum(grid [][]int) int { m, n := len(grid), len(grid[0]) f := make([][]int, m) for i := range f { f[i] = make([]int, n) } f[0][0] = grid[0][0] for i := 1; i < m; i++ { f[i][0] = f[i-1][0] + grid[i][0] } for j := 1; j < n; j++ { f[0][j] = f[0][j-1] + grid[0][j] } for i := 1; i < m; i++ { for j := 1; j < n; j++ { f[i][j] = min(f[i-1][j], f[i][j-1]) + grid[i][j] } } return f[m-1][n-1] }
64
Minimum Path Sum
Medium
<p>Given a <code>m x n</code> <code>grid</code> filled with non-negative numbers, find a path from top left to bottom right, which minimizes the sum of all numbers along its path.</p> <p><strong>Note:</strong> You can only move either down or right at any point in time.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0064.Minimum%20Path%20Sum/images/minpath.jpg" style="width: 242px; height: 242px;" /> <pre> <strong>Input:</strong> grid = [[1,3,1],[1,5,1],[4,2,1]] <strong>Output:</strong> 7 <strong>Explanation:</strong> Because the path 1 &rarr; 3 &rarr; 1 &rarr; 1 &rarr; 1 minimizes the sum. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> grid = [[1,2,3],[4,5,6]] <strong>Output:</strong> 12 </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>m == grid.length</code></li> <li><code>n == grid[i].length</code></li> <li><code>1 &lt;= m, n &lt;= 200</code></li> <li><code>0 &lt;= grid[i][j] &lt;= 200</code></li> </ul>
Array; Dynamic Programming; Matrix
Java
class Solution { public int minPathSum(int[][] grid) { int m = grid.length, n = grid[0].length; int[][] f = new int[m][n]; f[0][0] = grid[0][0]; for (int i = 1; i < m; ++i) { f[i][0] = f[i - 1][0] + grid[i][0]; } for (int j = 1; j < n; ++j) { f[0][j] = f[0][j - 1] + grid[0][j]; } for (int i = 1; i < m; ++i) { for (int j = 1; j < n; ++j) { f[i][j] = Math.min(f[i - 1][j], f[i][j - 1]) + grid[i][j]; } } return f[m - 1][n - 1]; } }
64
Minimum Path Sum
Medium
<p>Given a <code>m x n</code> <code>grid</code> filled with non-negative numbers, find a path from top left to bottom right, which minimizes the sum of all numbers along its path.</p> <p><strong>Note:</strong> You can only move either down or right at any point in time.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0064.Minimum%20Path%20Sum/images/minpath.jpg" style="width: 242px; height: 242px;" /> <pre> <strong>Input:</strong> grid = [[1,3,1],[1,5,1],[4,2,1]] <strong>Output:</strong> 7 <strong>Explanation:</strong> Because the path 1 &rarr; 3 &rarr; 1 &rarr; 1 &rarr; 1 minimizes the sum. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> grid = [[1,2,3],[4,5,6]] <strong>Output:</strong> 12 </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>m == grid.length</code></li> <li><code>n == grid[i].length</code></li> <li><code>1 &lt;= m, n &lt;= 200</code></li> <li><code>0 &lt;= grid[i][j] &lt;= 200</code></li> </ul>
Array; Dynamic Programming; Matrix
JavaScript
/** * @param {number[][]} grid * @return {number} */ var minPathSum = function (grid) { const m = grid.length; const n = grid[0].length; const f = Array(m) .fill(0) .map(() => Array(n).fill(0)); f[0][0] = grid[0][0]; for (let i = 1; i < m; ++i) { f[i][0] = f[i - 1][0] + grid[i][0]; } for (let j = 1; j < n; ++j) { f[0][j] = f[0][j - 1] + grid[0][j]; } for (let i = 1; i < m; ++i) { for (let j = 1; j < n; ++j) { f[i][j] = Math.min(f[i - 1][j], f[i][j - 1]) + grid[i][j]; } } return f[m - 1][n - 1]; };
64
Minimum Path Sum
Medium
<p>Given a <code>m x n</code> <code>grid</code> filled with non-negative numbers, find a path from top left to bottom right, which minimizes the sum of all numbers along its path.</p> <p><strong>Note:</strong> You can only move either down or right at any point in time.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0064.Minimum%20Path%20Sum/images/minpath.jpg" style="width: 242px; height: 242px;" /> <pre> <strong>Input:</strong> grid = [[1,3,1],[1,5,1],[4,2,1]] <strong>Output:</strong> 7 <strong>Explanation:</strong> Because the path 1 &rarr; 3 &rarr; 1 &rarr; 1 &rarr; 1 minimizes the sum. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> grid = [[1,2,3],[4,5,6]] <strong>Output:</strong> 12 </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>m == grid.length</code></li> <li><code>n == grid[i].length</code></li> <li><code>1 &lt;= m, n &lt;= 200</code></li> <li><code>0 &lt;= grid[i][j] &lt;= 200</code></li> </ul>
Array; Dynamic Programming; Matrix
Python
class Solution: def minPathSum(self, grid: List[List[int]]) -> int: m, n = len(grid), len(grid[0]) f = [[0] * n for _ in range(m)] f[0][0] = grid[0][0] for i in range(1, m): f[i][0] = f[i - 1][0] + grid[i][0] for j in range(1, n): f[0][j] = f[0][j - 1] + grid[0][j] for i in range(1, m): for j in range(1, n): f[i][j] = min(f[i - 1][j], f[i][j - 1]) + grid[i][j] return f[-1][-1]
64
Minimum Path Sum
Medium
<p>Given a <code>m x n</code> <code>grid</code> filled with non-negative numbers, find a path from top left to bottom right, which minimizes the sum of all numbers along its path.</p> <p><strong>Note:</strong> You can only move either down or right at any point in time.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0064.Minimum%20Path%20Sum/images/minpath.jpg" style="width: 242px; height: 242px;" /> <pre> <strong>Input:</strong> grid = [[1,3,1],[1,5,1],[4,2,1]] <strong>Output:</strong> 7 <strong>Explanation:</strong> Because the path 1 &rarr; 3 &rarr; 1 &rarr; 1 &rarr; 1 minimizes the sum. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> grid = [[1,2,3],[4,5,6]] <strong>Output:</strong> 12 </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>m == grid.length</code></li> <li><code>n == grid[i].length</code></li> <li><code>1 &lt;= m, n &lt;= 200</code></li> <li><code>0 &lt;= grid[i][j] &lt;= 200</code></li> </ul>
Array; Dynamic Programming; Matrix
Rust
impl Solution { pub fn min_path_sum(mut grid: Vec<Vec<i32>>) -> i32 { let m = grid.len(); let n = grid[0].len(); for i in 1..m { grid[i][0] += grid[i - 1][0]; } for i in 1..n { grid[0][i] += grid[0][i - 1]; } for i in 1..m { for j in 1..n { grid[i][j] += grid[i][j - 1].min(grid[i - 1][j]); } } grid[m - 1][n - 1] } }
64
Minimum Path Sum
Medium
<p>Given a <code>m x n</code> <code>grid</code> filled with non-negative numbers, find a path from top left to bottom right, which minimizes the sum of all numbers along its path.</p> <p><strong>Note:</strong> You can only move either down or right at any point in time.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0064.Minimum%20Path%20Sum/images/minpath.jpg" style="width: 242px; height: 242px;" /> <pre> <strong>Input:</strong> grid = [[1,3,1],[1,5,1],[4,2,1]] <strong>Output:</strong> 7 <strong>Explanation:</strong> Because the path 1 &rarr; 3 &rarr; 1 &rarr; 1 &rarr; 1 minimizes the sum. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> grid = [[1,2,3],[4,5,6]] <strong>Output:</strong> 12 </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>m == grid.length</code></li> <li><code>n == grid[i].length</code></li> <li><code>1 &lt;= m, n &lt;= 200</code></li> <li><code>0 &lt;= grid[i][j] &lt;= 200</code></li> </ul>
Array; Dynamic Programming; Matrix
TypeScript
function minPathSum(grid: number[][]): number { const m = grid.length; const n = grid[0].length; const f: number[][] = Array(m) .fill(0) .map(() => Array(n).fill(0)); f[0][0] = grid[0][0]; for (let i = 1; i < m; ++i) { f[i][0] = f[i - 1][0] + grid[i][0]; } for (let j = 1; j < n; ++j) { f[0][j] = f[0][j - 1] + grid[0][j]; } for (let i = 1; i < m; ++i) { for (let j = 1; j < n; ++j) { f[i][j] = Math.min(f[i - 1][j], f[i][j - 1]) + grid[i][j]; } } return f[m - 1][n - 1]; }
65
Valid Number
Hard
<p>Given a string <code>s</code>, return whether <code>s</code> is a <strong>valid number</strong>.<br /> <br /> For example, all the following are valid numbers: <code>&quot;2&quot;, &quot;0089&quot;, &quot;-0.1&quot;, &quot;+3.14&quot;, &quot;4.&quot;, &quot;-.9&quot;, &quot;2e10&quot;, &quot;-90E3&quot;, &quot;3e+7&quot;, &quot;+6e-1&quot;, &quot;53.5e93&quot;, &quot;-123.456e789&quot;</code>, while the following are not valid numbers: <code>&quot;abc&quot;, &quot;1a&quot;, &quot;1e&quot;, &quot;e3&quot;, &quot;99e2.5&quot;, &quot;--6&quot;, &quot;-+3&quot;, &quot;95a54e53&quot;</code>.</p> <p>Formally, a&nbsp;<strong>valid number</strong> is defined using one of the following definitions:</p> <ol> <li>An <strong>integer number</strong> followed by an <strong>optional exponent</strong>.</li> <li>A <strong>decimal number</strong> followed by an <strong>optional exponent</strong>.</li> </ol> <p>An <strong>integer number</strong> is defined with an <strong>optional sign</strong> <code>&#39;-&#39;</code> or <code>&#39;+&#39;</code> followed by <strong>digits</strong>.</p> <p>A <strong>decimal number</strong> is defined with an <strong>optional sign</strong> <code>&#39;-&#39;</code> or <code>&#39;+&#39;</code> followed by one of the following definitions:</p> <ol> <li><strong>Digits</strong> followed by a <strong>dot</strong> <code>&#39;.&#39;</code>.</li> <li><strong>Digits</strong> followed by a <strong>dot</strong> <code>&#39;.&#39;</code> followed by <strong>digits</strong>.</li> <li>A <strong>dot</strong> <code>&#39;.&#39;</code> followed by <strong>digits</strong>.</li> </ol> <p>An <strong>exponent</strong> is defined with an <strong>exponent notation</strong> <code>&#39;e&#39;</code> or <code>&#39;E&#39;</code> followed by an <strong>integer number</strong>.</p> <p>The <strong>digits</strong> are defined as one or more digits.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;e&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;.&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= s.length &lt;= 20</code></li> <li><code>s</code> consists of only English letters (both uppercase and lowercase), digits (<code>0-9</code>), plus <code>&#39;+&#39;</code>, minus <code>&#39;-&#39;</code>, or dot <code>&#39;.&#39;</code>.</li> </ul>
String
C++
class Solution { public: bool isNumber(string s) { int n = s.size(); int i = 0; if (s[i] == '+' || s[i] == '-') ++i; if (i == n) return false; if (s[i] == '.' && (i + 1 == n || s[i + 1] == 'e' || s[i + 1] == 'E')) return false; int dot = 0, e = 0; for (int j = i; j < n; ++j) { if (s[j] == '.') { if (e || dot) return false; ++dot; } else if (s[j] == 'e' || s[j] == 'E') { if (e || j == i || j == n - 1) return false; ++e; if (s[j + 1] == '+' || s[j + 1] == '-') { if (++j == n - 1) return false; } } else if (s[j] < '0' || s[j] > '9') return false; } return true; } };
65
Valid Number
Hard
<p>Given a string <code>s</code>, return whether <code>s</code> is a <strong>valid number</strong>.<br /> <br /> For example, all the following are valid numbers: <code>&quot;2&quot;, &quot;0089&quot;, &quot;-0.1&quot;, &quot;+3.14&quot;, &quot;4.&quot;, &quot;-.9&quot;, &quot;2e10&quot;, &quot;-90E3&quot;, &quot;3e+7&quot;, &quot;+6e-1&quot;, &quot;53.5e93&quot;, &quot;-123.456e789&quot;</code>, while the following are not valid numbers: <code>&quot;abc&quot;, &quot;1a&quot;, &quot;1e&quot;, &quot;e3&quot;, &quot;99e2.5&quot;, &quot;--6&quot;, &quot;-+3&quot;, &quot;95a54e53&quot;</code>.</p> <p>Formally, a&nbsp;<strong>valid number</strong> is defined using one of the following definitions:</p> <ol> <li>An <strong>integer number</strong> followed by an <strong>optional exponent</strong>.</li> <li>A <strong>decimal number</strong> followed by an <strong>optional exponent</strong>.</li> </ol> <p>An <strong>integer number</strong> is defined with an <strong>optional sign</strong> <code>&#39;-&#39;</code> or <code>&#39;+&#39;</code> followed by <strong>digits</strong>.</p> <p>A <strong>decimal number</strong> is defined with an <strong>optional sign</strong> <code>&#39;-&#39;</code> or <code>&#39;+&#39;</code> followed by one of the following definitions:</p> <ol> <li><strong>Digits</strong> followed by a <strong>dot</strong> <code>&#39;.&#39;</code>.</li> <li><strong>Digits</strong> followed by a <strong>dot</strong> <code>&#39;.&#39;</code> followed by <strong>digits</strong>.</li> <li>A <strong>dot</strong> <code>&#39;.&#39;</code> followed by <strong>digits</strong>.</li> </ol> <p>An <strong>exponent</strong> is defined with an <strong>exponent notation</strong> <code>&#39;e&#39;</code> or <code>&#39;E&#39;</code> followed by an <strong>integer number</strong>.</p> <p>The <strong>digits</strong> are defined as one or more digits.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;e&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;.&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= s.length &lt;= 20</code></li> <li><code>s</code> consists of only English letters (both uppercase and lowercase), digits (<code>0-9</code>), plus <code>&#39;+&#39;</code>, minus <code>&#39;-&#39;</code>, or dot <code>&#39;.&#39;</code>.</li> </ul>
String
C#
using System.Text.RegularExpressions; public class Solution { private readonly Regex _isNumber_Regex = new Regex(@"^\s*[+-]?(\d+(\.\d*)?|\.\d+)([Ee][+-]?\d+)?\s*$"); public bool IsNumber(string s) { return _isNumber_Regex.IsMatch(s); } }
65
Valid Number
Hard
<p>Given a string <code>s</code>, return whether <code>s</code> is a <strong>valid number</strong>.<br /> <br /> For example, all the following are valid numbers: <code>&quot;2&quot;, &quot;0089&quot;, &quot;-0.1&quot;, &quot;+3.14&quot;, &quot;4.&quot;, &quot;-.9&quot;, &quot;2e10&quot;, &quot;-90E3&quot;, &quot;3e+7&quot;, &quot;+6e-1&quot;, &quot;53.5e93&quot;, &quot;-123.456e789&quot;</code>, while the following are not valid numbers: <code>&quot;abc&quot;, &quot;1a&quot;, &quot;1e&quot;, &quot;e3&quot;, &quot;99e2.5&quot;, &quot;--6&quot;, &quot;-+3&quot;, &quot;95a54e53&quot;</code>.</p> <p>Formally, a&nbsp;<strong>valid number</strong> is defined using one of the following definitions:</p> <ol> <li>An <strong>integer number</strong> followed by an <strong>optional exponent</strong>.</li> <li>A <strong>decimal number</strong> followed by an <strong>optional exponent</strong>.</li> </ol> <p>An <strong>integer number</strong> is defined with an <strong>optional sign</strong> <code>&#39;-&#39;</code> or <code>&#39;+&#39;</code> followed by <strong>digits</strong>.</p> <p>A <strong>decimal number</strong> is defined with an <strong>optional sign</strong> <code>&#39;-&#39;</code> or <code>&#39;+&#39;</code> followed by one of the following definitions:</p> <ol> <li><strong>Digits</strong> followed by a <strong>dot</strong> <code>&#39;.&#39;</code>.</li> <li><strong>Digits</strong> followed by a <strong>dot</strong> <code>&#39;.&#39;</code> followed by <strong>digits</strong>.</li> <li>A <strong>dot</strong> <code>&#39;.&#39;</code> followed by <strong>digits</strong>.</li> </ol> <p>An <strong>exponent</strong> is defined with an <strong>exponent notation</strong> <code>&#39;e&#39;</code> or <code>&#39;E&#39;</code> followed by an <strong>integer number</strong>.</p> <p>The <strong>digits</strong> are defined as one or more digits.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;e&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;.&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= s.length &lt;= 20</code></li> <li><code>s</code> consists of only English letters (both uppercase and lowercase), digits (<code>0-9</code>), plus <code>&#39;+&#39;</code>, minus <code>&#39;-&#39;</code>, or dot <code>&#39;.&#39;</code>.</li> </ul>
String
Go
func isNumber(s string) bool { i, n := 0, len(s) if s[i] == '+' || s[i] == '-' { i++ } if i == n { return false } if s[i] == '.' && (i+1 == n || s[i+1] == 'e' || s[i+1] == 'E') { return false } var dot, e int for j := i; j < n; j++ { if s[j] == '.' { if e > 0 || dot > 0 { return false } dot++ } else if s[j] == 'e' || s[j] == 'E' { if e > 0 || j == i || j == n-1 { return false } e++ if s[j+1] == '+' || s[j+1] == '-' { j++ if j == n-1 { return false } } } else if s[j] < '0' || s[j] > '9' { return false } } return true }
65
Valid Number
Hard
<p>Given a string <code>s</code>, return whether <code>s</code> is a <strong>valid number</strong>.<br /> <br /> For example, all the following are valid numbers: <code>&quot;2&quot;, &quot;0089&quot;, &quot;-0.1&quot;, &quot;+3.14&quot;, &quot;4.&quot;, &quot;-.9&quot;, &quot;2e10&quot;, &quot;-90E3&quot;, &quot;3e+7&quot;, &quot;+6e-1&quot;, &quot;53.5e93&quot;, &quot;-123.456e789&quot;</code>, while the following are not valid numbers: <code>&quot;abc&quot;, &quot;1a&quot;, &quot;1e&quot;, &quot;e3&quot;, &quot;99e2.5&quot;, &quot;--6&quot;, &quot;-+3&quot;, &quot;95a54e53&quot;</code>.</p> <p>Formally, a&nbsp;<strong>valid number</strong> is defined using one of the following definitions:</p> <ol> <li>An <strong>integer number</strong> followed by an <strong>optional exponent</strong>.</li> <li>A <strong>decimal number</strong> followed by an <strong>optional exponent</strong>.</li> </ol> <p>An <strong>integer number</strong> is defined with an <strong>optional sign</strong> <code>&#39;-&#39;</code> or <code>&#39;+&#39;</code> followed by <strong>digits</strong>.</p> <p>A <strong>decimal number</strong> is defined with an <strong>optional sign</strong> <code>&#39;-&#39;</code> or <code>&#39;+&#39;</code> followed by one of the following definitions:</p> <ol> <li><strong>Digits</strong> followed by a <strong>dot</strong> <code>&#39;.&#39;</code>.</li> <li><strong>Digits</strong> followed by a <strong>dot</strong> <code>&#39;.&#39;</code> followed by <strong>digits</strong>.</li> <li>A <strong>dot</strong> <code>&#39;.&#39;</code> followed by <strong>digits</strong>.</li> </ol> <p>An <strong>exponent</strong> is defined with an <strong>exponent notation</strong> <code>&#39;e&#39;</code> or <code>&#39;E&#39;</code> followed by an <strong>integer number</strong>.</p> <p>The <strong>digits</strong> are defined as one or more digits.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;e&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;.&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= s.length &lt;= 20</code></li> <li><code>s</code> consists of only English letters (both uppercase and lowercase), digits (<code>0-9</code>), plus <code>&#39;+&#39;</code>, minus <code>&#39;-&#39;</code>, or dot <code>&#39;.&#39;</code>.</li> </ul>
String
Java
class Solution { public boolean isNumber(String s) { int n = s.length(); int i = 0; if (s.charAt(i) == '+' || s.charAt(i) == '-') { ++i; } if (i == n) { return false; } if (s.charAt(i) == '.' && (i + 1 == n || s.charAt(i + 1) == 'e' || s.charAt(i + 1) == 'E')) { return false; } int dot = 0, e = 0; for (int j = i; j < n; ++j) { if (s.charAt(j) == '.') { if (e > 0 || dot > 0) { return false; } ++dot; } else if (s.charAt(j) == 'e' || s.charAt(j) == 'E') { if (e > 0 || j == i || j == n - 1) { return false; } ++e; if (s.charAt(j + 1) == '+' || s.charAt(j + 1) == '-') { if (++j == n - 1) { return false; } } } else if (s.charAt(j) < '0' || s.charAt(j) > '9') { return false; } } return true; } }
65
Valid Number
Hard
<p>Given a string <code>s</code>, return whether <code>s</code> is a <strong>valid number</strong>.<br /> <br /> For example, all the following are valid numbers: <code>&quot;2&quot;, &quot;0089&quot;, &quot;-0.1&quot;, &quot;+3.14&quot;, &quot;4.&quot;, &quot;-.9&quot;, &quot;2e10&quot;, &quot;-90E3&quot;, &quot;3e+7&quot;, &quot;+6e-1&quot;, &quot;53.5e93&quot;, &quot;-123.456e789&quot;</code>, while the following are not valid numbers: <code>&quot;abc&quot;, &quot;1a&quot;, &quot;1e&quot;, &quot;e3&quot;, &quot;99e2.5&quot;, &quot;--6&quot;, &quot;-+3&quot;, &quot;95a54e53&quot;</code>.</p> <p>Formally, a&nbsp;<strong>valid number</strong> is defined using one of the following definitions:</p> <ol> <li>An <strong>integer number</strong> followed by an <strong>optional exponent</strong>.</li> <li>A <strong>decimal number</strong> followed by an <strong>optional exponent</strong>.</li> </ol> <p>An <strong>integer number</strong> is defined with an <strong>optional sign</strong> <code>&#39;-&#39;</code> or <code>&#39;+&#39;</code> followed by <strong>digits</strong>.</p> <p>A <strong>decimal number</strong> is defined with an <strong>optional sign</strong> <code>&#39;-&#39;</code> or <code>&#39;+&#39;</code> followed by one of the following definitions:</p> <ol> <li><strong>Digits</strong> followed by a <strong>dot</strong> <code>&#39;.&#39;</code>.</li> <li><strong>Digits</strong> followed by a <strong>dot</strong> <code>&#39;.&#39;</code> followed by <strong>digits</strong>.</li> <li>A <strong>dot</strong> <code>&#39;.&#39;</code> followed by <strong>digits</strong>.</li> </ol> <p>An <strong>exponent</strong> is defined with an <strong>exponent notation</strong> <code>&#39;e&#39;</code> or <code>&#39;E&#39;</code> followed by an <strong>integer number</strong>.</p> <p>The <strong>digits</strong> are defined as one or more digits.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;e&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;.&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= s.length &lt;= 20</code></li> <li><code>s</code> consists of only English letters (both uppercase and lowercase), digits (<code>0-9</code>), plus <code>&#39;+&#39;</code>, minus <code>&#39;-&#39;</code>, or dot <code>&#39;.&#39;</code>.</li> </ul>
String
Python
class Solution: def isNumber(self, s: str) -> bool: n = len(s) i = 0 if s[i] in '+-': i += 1 if i == n: return False if s[i] == '.' and (i + 1 == n or s[i + 1] in 'eE'): return False dot = e = 0 j = i while j < n: if s[j] == '.': if e or dot: return False dot += 1 elif s[j] in 'eE': if e or j == i or j == n - 1: return False e += 1 if s[j + 1] in '+-': j += 1 if j == n - 1: return False elif not s[j].isnumeric(): return False j += 1 return True
65
Valid Number
Hard
<p>Given a string <code>s</code>, return whether <code>s</code> is a <strong>valid number</strong>.<br /> <br /> For example, all the following are valid numbers: <code>&quot;2&quot;, &quot;0089&quot;, &quot;-0.1&quot;, &quot;+3.14&quot;, &quot;4.&quot;, &quot;-.9&quot;, &quot;2e10&quot;, &quot;-90E3&quot;, &quot;3e+7&quot;, &quot;+6e-1&quot;, &quot;53.5e93&quot;, &quot;-123.456e789&quot;</code>, while the following are not valid numbers: <code>&quot;abc&quot;, &quot;1a&quot;, &quot;1e&quot;, &quot;e3&quot;, &quot;99e2.5&quot;, &quot;--6&quot;, &quot;-+3&quot;, &quot;95a54e53&quot;</code>.</p> <p>Formally, a&nbsp;<strong>valid number</strong> is defined using one of the following definitions:</p> <ol> <li>An <strong>integer number</strong> followed by an <strong>optional exponent</strong>.</li> <li>A <strong>decimal number</strong> followed by an <strong>optional exponent</strong>.</li> </ol> <p>An <strong>integer number</strong> is defined with an <strong>optional sign</strong> <code>&#39;-&#39;</code> or <code>&#39;+&#39;</code> followed by <strong>digits</strong>.</p> <p>A <strong>decimal number</strong> is defined with an <strong>optional sign</strong> <code>&#39;-&#39;</code> or <code>&#39;+&#39;</code> followed by one of the following definitions:</p> <ol> <li><strong>Digits</strong> followed by a <strong>dot</strong> <code>&#39;.&#39;</code>.</li> <li><strong>Digits</strong> followed by a <strong>dot</strong> <code>&#39;.&#39;</code> followed by <strong>digits</strong>.</li> <li>A <strong>dot</strong> <code>&#39;.&#39;</code> followed by <strong>digits</strong>.</li> </ol> <p>An <strong>exponent</strong> is defined with an <strong>exponent notation</strong> <code>&#39;e&#39;</code> or <code>&#39;E&#39;</code> followed by an <strong>integer number</strong>.</p> <p>The <strong>digits</strong> are defined as one or more digits.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;e&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;.&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= s.length &lt;= 20</code></li> <li><code>s</code> consists of only English letters (both uppercase and lowercase), digits (<code>0-9</code>), plus <code>&#39;+&#39;</code>, minus <code>&#39;-&#39;</code>, or dot <code>&#39;.&#39;</code>.</li> </ul>
String
Rust
impl Solution { pub fn is_number(s: String) -> bool { let mut i = 0; let n = s.len(); if let Some(c) = s.chars().nth(i) { if c == '+' || c == '-' { i += 1; if i == n { return false; } } } if let Some(x) = s.chars().nth(i) { if x == '.' && (i + 1 == n || (if let Some(m) = s.chars().nth(i + 1) { m == 'e' || m == 'E' } else { false })) { return false; } } let mut dot = 0; let mut e = 0; let mut j = i; while j < n { if let Some(c) = s.chars().nth(j) { if c == '.' { if e > 0 || dot > 0 { return false; } dot += 1; } else if c == 'e' || c == 'E' { if e > 0 || j == i || j == n - 1 { return false; } e += 1; if let Some(x) = s.chars().nth(j + 1) { if x == '+' || x == '-' { j += 1; if j == n - 1 { return false; } } } } else if !c.is_ascii_digit() { return false; } } j += 1; } true } }
66
Plus One
Easy
<p>You are given a <strong>large integer</strong> represented as an integer array <code>digits</code>, where each <code>digits[i]</code> is the <code>i<sup>th</sup></code> digit of the integer. The digits are ordered from most significant to least significant in left-to-right order. The large integer does not contain any leading <code>0</code>&#39;s.</p> <p>Increment the large integer by one and return <em>the resulting array of digits</em>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> digits = [1,2,3] <strong>Output:</strong> [1,2,4] <strong>Explanation:</strong> The array represents the integer 123. Incrementing by one gives 123 + 1 = 124. Thus, the result should be [1,2,4]. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> digits = [4,3,2,1] <strong>Output:</strong> [4,3,2,2] <strong>Explanation:</strong> The array represents the integer 4321. Incrementing by one gives 4321 + 1 = 4322. Thus, the result should be [4,3,2,2]. </pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> digits = [9] <strong>Output:</strong> [1,0] <strong>Explanation:</strong> The array represents the integer 9. Incrementing by one gives 9 + 1 = 10. Thus, the result should be [1,0]. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= digits.length &lt;= 100</code></li> <li><code>0 &lt;= digits[i] &lt;= 9</code></li> <li><code>digits</code> does not contain any leading <code>0</code>&#39;s.</li> </ul>
Array; Math
C++
class Solution { public: vector<int> plusOne(vector<int>& digits) { for (int i = digits.size() - 1; i >= 0; --i) { ++digits[i]; digits[i] %= 10; if (digits[i] != 0) return digits; } digits.insert(digits.begin(), 1); return digits; } };
66
Plus One
Easy
<p>You are given a <strong>large integer</strong> represented as an integer array <code>digits</code>, where each <code>digits[i]</code> is the <code>i<sup>th</sup></code> digit of the integer. The digits are ordered from most significant to least significant in left-to-right order. The large integer does not contain any leading <code>0</code>&#39;s.</p> <p>Increment the large integer by one and return <em>the resulting array of digits</em>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> digits = [1,2,3] <strong>Output:</strong> [1,2,4] <strong>Explanation:</strong> The array represents the integer 123. Incrementing by one gives 123 + 1 = 124. Thus, the result should be [1,2,4]. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> digits = [4,3,2,1] <strong>Output:</strong> [4,3,2,2] <strong>Explanation:</strong> The array represents the integer 4321. Incrementing by one gives 4321 + 1 = 4322. Thus, the result should be [4,3,2,2]. </pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> digits = [9] <strong>Output:</strong> [1,0] <strong>Explanation:</strong> The array represents the integer 9. Incrementing by one gives 9 + 1 = 10. Thus, the result should be [1,0]. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= digits.length &lt;= 100</code></li> <li><code>0 &lt;= digits[i] &lt;= 9</code></li> <li><code>digits</code> does not contain any leading <code>0</code>&#39;s.</li> </ul>
Array; Math
Go
func plusOne(digits []int) []int { n := len(digits) for i := n - 1; i >= 0; i-- { digits[i]++ digits[i] %= 10 if digits[i] != 0 { return digits } } return append([]int{1}, digits...) }
66
Plus One
Easy
<p>You are given a <strong>large integer</strong> represented as an integer array <code>digits</code>, where each <code>digits[i]</code> is the <code>i<sup>th</sup></code> digit of the integer. The digits are ordered from most significant to least significant in left-to-right order. The large integer does not contain any leading <code>0</code>&#39;s.</p> <p>Increment the large integer by one and return <em>the resulting array of digits</em>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> digits = [1,2,3] <strong>Output:</strong> [1,2,4] <strong>Explanation:</strong> The array represents the integer 123. Incrementing by one gives 123 + 1 = 124. Thus, the result should be [1,2,4]. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> digits = [4,3,2,1] <strong>Output:</strong> [4,3,2,2] <strong>Explanation:</strong> The array represents the integer 4321. Incrementing by one gives 4321 + 1 = 4322. Thus, the result should be [4,3,2,2]. </pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> digits = [9] <strong>Output:</strong> [1,0] <strong>Explanation:</strong> The array represents the integer 9. Incrementing by one gives 9 + 1 = 10. Thus, the result should be [1,0]. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= digits.length &lt;= 100</code></li> <li><code>0 &lt;= digits[i] &lt;= 9</code></li> <li><code>digits</code> does not contain any leading <code>0</code>&#39;s.</li> </ul>
Array; Math
Java
class Solution { public int[] plusOne(int[] digits) { int n = digits.length; for (int i = n - 1; i >= 0; --i) { ++digits[i]; digits[i] %= 10; if (digits[i] != 0) { return digits; } } digits = new int[n + 1]; digits[0] = 1; return digits; } }
66
Plus One
Easy
<p>You are given a <strong>large integer</strong> represented as an integer array <code>digits</code>, where each <code>digits[i]</code> is the <code>i<sup>th</sup></code> digit of the integer. The digits are ordered from most significant to least significant in left-to-right order. The large integer does not contain any leading <code>0</code>&#39;s.</p> <p>Increment the large integer by one and return <em>the resulting array of digits</em>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> digits = [1,2,3] <strong>Output:</strong> [1,2,4] <strong>Explanation:</strong> The array represents the integer 123. Incrementing by one gives 123 + 1 = 124. Thus, the result should be [1,2,4]. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> digits = [4,3,2,1] <strong>Output:</strong> [4,3,2,2] <strong>Explanation:</strong> The array represents the integer 4321. Incrementing by one gives 4321 + 1 = 4322. Thus, the result should be [4,3,2,2]. </pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> digits = [9] <strong>Output:</strong> [1,0] <strong>Explanation:</strong> The array represents the integer 9. Incrementing by one gives 9 + 1 = 10. Thus, the result should be [1,0]. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= digits.length &lt;= 100</code></li> <li><code>0 &lt;= digits[i] &lt;= 9</code></li> <li><code>digits</code> does not contain any leading <code>0</code>&#39;s.</li> </ul>
Array; Math
JavaScript
/** * @param {number[]} digits * @return {number[]} */ var plusOne = function (digits) { for (let i = digits.length - 1; i >= 0; --i) { ++digits[i]; digits[i] %= 10; if (digits[i] != 0) { return digits; } } return [1, ...digits]; };
66
Plus One
Easy
<p>You are given a <strong>large integer</strong> represented as an integer array <code>digits</code>, where each <code>digits[i]</code> is the <code>i<sup>th</sup></code> digit of the integer. The digits are ordered from most significant to least significant in left-to-right order. The large integer does not contain any leading <code>0</code>&#39;s.</p> <p>Increment the large integer by one and return <em>the resulting array of digits</em>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> digits = [1,2,3] <strong>Output:</strong> [1,2,4] <strong>Explanation:</strong> The array represents the integer 123. Incrementing by one gives 123 + 1 = 124. Thus, the result should be [1,2,4]. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> digits = [4,3,2,1] <strong>Output:</strong> [4,3,2,2] <strong>Explanation:</strong> The array represents the integer 4321. Incrementing by one gives 4321 + 1 = 4322. Thus, the result should be [4,3,2,2]. </pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> digits = [9] <strong>Output:</strong> [1,0] <strong>Explanation:</strong> The array represents the integer 9. Incrementing by one gives 9 + 1 = 10. Thus, the result should be [1,0]. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= digits.length &lt;= 100</code></li> <li><code>0 &lt;= digits[i] &lt;= 9</code></li> <li><code>digits</code> does not contain any leading <code>0</code>&#39;s.</li> </ul>
Array; Math
Python
class Solution: def plusOne(self, digits: List[int]) -> List[int]: n = len(digits) for i in range(n - 1, -1, -1): digits[i] += 1 digits[i] %= 10 if digits[i] != 0: return digits return [1] + digits
66
Plus One
Easy
<p>You are given a <strong>large integer</strong> represented as an integer array <code>digits</code>, where each <code>digits[i]</code> is the <code>i<sup>th</sup></code> digit of the integer. The digits are ordered from most significant to least significant in left-to-right order. The large integer does not contain any leading <code>0</code>&#39;s.</p> <p>Increment the large integer by one and return <em>the resulting array of digits</em>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> digits = [1,2,3] <strong>Output:</strong> [1,2,4] <strong>Explanation:</strong> The array represents the integer 123. Incrementing by one gives 123 + 1 = 124. Thus, the result should be [1,2,4]. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> digits = [4,3,2,1] <strong>Output:</strong> [4,3,2,2] <strong>Explanation:</strong> The array represents the integer 4321. Incrementing by one gives 4321 + 1 = 4322. Thus, the result should be [4,3,2,2]. </pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> digits = [9] <strong>Output:</strong> [1,0] <strong>Explanation:</strong> The array represents the integer 9. Incrementing by one gives 9 + 1 = 10. Thus, the result should be [1,0]. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= digits.length &lt;= 100</code></li> <li><code>0 &lt;= digits[i] &lt;= 9</code></li> <li><code>digits</code> does not contain any leading <code>0</code>&#39;s.</li> </ul>
Array; Math
Rust
impl Solution { pub fn plus_one(mut digits: Vec<i32>) -> Vec<i32> { let n = digits.len(); for i in (0..n).rev() { digits[i] += 1; if 10 > digits[i] { return digits; } digits[i] %= 10; } digits.insert(0, 1); digits } }
66
Plus One
Easy
<p>You are given a <strong>large integer</strong> represented as an integer array <code>digits</code>, where each <code>digits[i]</code> is the <code>i<sup>th</sup></code> digit of the integer. The digits are ordered from most significant to least significant in left-to-right order. The large integer does not contain any leading <code>0</code>&#39;s.</p> <p>Increment the large integer by one and return <em>the resulting array of digits</em>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> digits = [1,2,3] <strong>Output:</strong> [1,2,4] <strong>Explanation:</strong> The array represents the integer 123. Incrementing by one gives 123 + 1 = 124. Thus, the result should be [1,2,4]. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> digits = [4,3,2,1] <strong>Output:</strong> [4,3,2,2] <strong>Explanation:</strong> The array represents the integer 4321. Incrementing by one gives 4321 + 1 = 4322. Thus, the result should be [4,3,2,2]. </pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> digits = [9] <strong>Output:</strong> [1,0] <strong>Explanation:</strong> The array represents the integer 9. Incrementing by one gives 9 + 1 = 10. Thus, the result should be [1,0]. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= digits.length &lt;= 100</code></li> <li><code>0 &lt;= digits[i] &lt;= 9</code></li> <li><code>digits</code> does not contain any leading <code>0</code>&#39;s.</li> </ul>
Array; Math
TypeScript
function plusOne(digits: number[]): number[] { const n = digits.length; for (let i = n - 1; i >= 0; i--) { if (10 > ++digits[i]) { return digits; } digits[i] %= 10; } return [1, ...digits]; }
67
Add Binary
Easy
<p>Given two binary strings <code>a</code> and <code>b</code>, return <em>their sum as a binary string</em>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre><strong>Input:</strong> a = "11", b = "1" <strong>Output:</strong> "100" </pre><p><strong class="example">Example 2:</strong></p> <pre><strong>Input:</strong> a = "1010", b = "1011" <strong>Output:</strong> "10101" </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= a.length, b.length &lt;= 10<sup>4</sup></code></li> <li><code>a</code> and <code>b</code> consist&nbsp;only of <code>&#39;0&#39;</code> or <code>&#39;1&#39;</code> characters.</li> <li>Each string does not contain leading zeros except for the zero itself.</li> </ul>
Bit Manipulation; Math; String; Simulation
C++
class Solution { public: string addBinary(string a, string b) { string ans; int i = a.size() - 1, j = b.size() - 1; for (int carry = 0; i >= 0 || j >= 0 || carry; --i, --j) { carry += (i >= 0 ? a[i] - '0' : 0) + (j >= 0 ? b[j] - '0' : 0); ans.push_back((carry % 2) + '0'); carry /= 2; } reverse(ans.begin(), ans.end()); return ans; } };
67
Add Binary
Easy
<p>Given two binary strings <code>a</code> and <code>b</code>, return <em>their sum as a binary string</em>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre><strong>Input:</strong> a = "11", b = "1" <strong>Output:</strong> "100" </pre><p><strong class="example">Example 2:</strong></p> <pre><strong>Input:</strong> a = "1010", b = "1011" <strong>Output:</strong> "10101" </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= a.length, b.length &lt;= 10<sup>4</sup></code></li> <li><code>a</code> and <code>b</code> consist&nbsp;only of <code>&#39;0&#39;</code> or <code>&#39;1&#39;</code> characters.</li> <li>Each string does not contain leading zeros except for the zero itself.</li> </ul>
Bit Manipulation; Math; String; Simulation
C#
public class Solution { public string AddBinary(string a, string b) { int i = a.Length - 1; int j = b.Length - 1; var sb = new StringBuilder(); for (int carry = 0; i >= 0 || j >= 0 || carry > 0; --i, --j) { carry += i >= 0 ? a[i] - '0' : 0; carry += j >= 0 ? b[j] - '0' : 0; sb.Append(carry % 2); carry /= 2; } var ans = sb.ToString().ToCharArray(); Array.Reverse(ans); return new string(ans); } }
67
Add Binary
Easy
<p>Given two binary strings <code>a</code> and <code>b</code>, return <em>their sum as a binary string</em>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre><strong>Input:</strong> a = "11", b = "1" <strong>Output:</strong> "100" </pre><p><strong class="example">Example 2:</strong></p> <pre><strong>Input:</strong> a = "1010", b = "1011" <strong>Output:</strong> "10101" </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= a.length, b.length &lt;= 10<sup>4</sup></code></li> <li><code>a</code> and <code>b</code> consist&nbsp;only of <code>&#39;0&#39;</code> or <code>&#39;1&#39;</code> characters.</li> <li>Each string does not contain leading zeros except for the zero itself.</li> </ul>
Bit Manipulation; Math; String; Simulation
Go
func addBinary(a string, b string) string { i, j := len(a)-1, len(b)-1 ans := []byte{} for carry := 0; i >= 0 || j >= 0 || carry > 0; i, j = i-1, j-1 { if i >= 0 { carry += int(a[i] - '0') } if j >= 0 { carry += int(b[j] - '0') } ans = append(ans, byte(carry%2+'0')) carry /= 2 } for i, j := 0, len(ans)-1; i < j; i, j = i+1, j-1 { ans[i], ans[j] = ans[j], ans[i] } return string(ans) }
67
Add Binary
Easy
<p>Given two binary strings <code>a</code> and <code>b</code>, return <em>their sum as a binary string</em>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre><strong>Input:</strong> a = "11", b = "1" <strong>Output:</strong> "100" </pre><p><strong class="example">Example 2:</strong></p> <pre><strong>Input:</strong> a = "1010", b = "1011" <strong>Output:</strong> "10101" </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= a.length, b.length &lt;= 10<sup>4</sup></code></li> <li><code>a</code> and <code>b</code> consist&nbsp;only of <code>&#39;0&#39;</code> or <code>&#39;1&#39;</code> characters.</li> <li>Each string does not contain leading zeros except for the zero itself.</li> </ul>
Bit Manipulation; Math; String; Simulation
Java
class Solution { public String addBinary(String a, String b) { var sb = new StringBuilder(); int i = a.length() - 1, j = b.length() - 1; for (int carry = 0; i >= 0 || j >= 0 || carry > 0; --i, --j) { carry += (i >= 0 ? a.charAt(i) - '0' : 0) + (j >= 0 ? b.charAt(j) - '0' : 0); sb.append(carry % 2); carry /= 2; } return sb.reverse().toString(); } }
67
Add Binary
Easy
<p>Given two binary strings <code>a</code> and <code>b</code>, return <em>their sum as a binary string</em>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre><strong>Input:</strong> a = "11", b = "1" <strong>Output:</strong> "100" </pre><p><strong class="example">Example 2:</strong></p> <pre><strong>Input:</strong> a = "1010", b = "1011" <strong>Output:</strong> "10101" </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= a.length, b.length &lt;= 10<sup>4</sup></code></li> <li><code>a</code> and <code>b</code> consist&nbsp;only of <code>&#39;0&#39;</code> or <code>&#39;1&#39;</code> characters.</li> <li>Each string does not contain leading zeros except for the zero itself.</li> </ul>
Bit Manipulation; Math; String; Simulation
Python
class Solution: def addBinary(self, a: str, b: str) -> str: return bin(int(a, 2) + int(b, 2))[2:]
67
Add Binary
Easy
<p>Given two binary strings <code>a</code> and <code>b</code>, return <em>their sum as a binary string</em>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre><strong>Input:</strong> a = "11", b = "1" <strong>Output:</strong> "100" </pre><p><strong class="example">Example 2:</strong></p> <pre><strong>Input:</strong> a = "1010", b = "1011" <strong>Output:</strong> "10101" </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= a.length, b.length &lt;= 10<sup>4</sup></code></li> <li><code>a</code> and <code>b</code> consist&nbsp;only of <code>&#39;0&#39;</code> or <code>&#39;1&#39;</code> characters.</li> <li>Each string does not contain leading zeros except for the zero itself.</li> </ul>
Bit Manipulation; Math; String; Simulation
Rust
impl Solution { pub fn add_binary(a: String, b: String) -> String { let mut i = (a.len() as i32) - 1; let mut j = (b.len() as i32) - 1; let mut carry = 0; let mut ans = String::new(); let a = a.as_bytes(); let b = b.as_bytes(); while i >= 0 || j >= 0 || carry > 0 { if i >= 0 { carry += a[i as usize] - b'0'; i -= 1; } if j >= 0 { carry += b[j as usize] - b'0'; j -= 1; } ans.push_str(&(carry % 2).to_string()); carry /= 2; } ans.chars().rev().collect() } }
67
Add Binary
Easy
<p>Given two binary strings <code>a</code> and <code>b</code>, return <em>their sum as a binary string</em>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre><strong>Input:</strong> a = "11", b = "1" <strong>Output:</strong> "100" </pre><p><strong class="example">Example 2:</strong></p> <pre><strong>Input:</strong> a = "1010", b = "1011" <strong>Output:</strong> "10101" </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= a.length, b.length &lt;= 10<sup>4</sup></code></li> <li><code>a</code> and <code>b</code> consist&nbsp;only of <code>&#39;0&#39;</code> or <code>&#39;1&#39;</code> characters.</li> <li>Each string does not contain leading zeros except for the zero itself.</li> </ul>
Bit Manipulation; Math; String; Simulation
TypeScript
function addBinary(a: string, b: string): string { return (BigInt('0b' + a) + BigInt('0b' + b)).toString(2); }
68
Text Justification
Hard
<p>Given an array of strings <code>words</code> and a width <code>maxWidth</code>, format the text such that each line has exactly <code>maxWidth</code> characters and is fully (left and right) justified.</p> <p>You should pack your words in a greedy approach; that is, pack as many words as you can in each line. Pad extra spaces <code>&#39; &#39;</code> when necessary so that each line has exactly <code>maxWidth</code> characters.</p> <p>Extra spaces between words should be distributed as evenly as possible. If the number of spaces on a line does not divide evenly between words, the empty slots on the left will be assigned more spaces than the slots on the right.</p> <p>For the last line of text, it should be left-justified, and no extra space is inserted between words.</p> <p><strong>Note:</strong></p> <ul> <li>A word is defined as a character sequence consisting of non-space characters only.</li> <li>Each word&#39;s length is guaranteed to be greater than <code>0</code> and not exceed <code>maxWidth</code>.</li> <li>The input array <code>words</code> contains at least one word.</li> </ul> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> words = [&quot;This&quot;, &quot;is&quot;, &quot;an&quot;, &quot;example&quot;, &quot;of&quot;, &quot;text&quot;, &quot;justification.&quot;], maxWidth = 16 <strong>Output:</strong> [ &nbsp; &nbsp;&quot;This &nbsp; &nbsp;is &nbsp; &nbsp;an&quot;, &nbsp; &nbsp;&quot;example &nbsp;of text&quot;, &nbsp; &nbsp;&quot;justification. &nbsp;&quot; ]</pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> words = [&quot;What&quot;,&quot;must&quot;,&quot;be&quot;,&quot;acknowledgment&quot;,&quot;shall&quot;,&quot;be&quot;], maxWidth = 16 <strong>Output:</strong> [ &nbsp; &quot;What &nbsp; must &nbsp; be&quot;, &nbsp; &quot;acknowledgment &nbsp;&quot;, &nbsp; &quot;shall be &nbsp; &nbsp; &nbsp; &nbsp;&quot; ] <strong>Explanation:</strong> Note that the last line is &quot;shall be &quot; instead of &quot;shall be&quot;, because the last line must be left-justified instead of fully-justified. Note that the second line is also left-justified because it contains only one word.</pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> words = [&quot;Science&quot;,&quot;is&quot;,&quot;what&quot;,&quot;we&quot;,&quot;understand&quot;,&quot;well&quot;,&quot;enough&quot;,&quot;to&quot;,&quot;explain&quot;,&quot;to&quot;,&quot;a&quot;,&quot;computer.&quot;,&quot;Art&quot;,&quot;is&quot;,&quot;everything&quot;,&quot;else&quot;,&quot;we&quot;,&quot;do&quot;], maxWidth = 20 <strong>Output:</strong> [ &nbsp; &quot;Science &nbsp;is &nbsp;what we&quot;, &quot;understand &nbsp; &nbsp; &nbsp;well&quot;, &nbsp; &quot;enough to explain to&quot;, &nbsp; &quot;a &nbsp;computer. &nbsp;Art is&quot;, &nbsp; &quot;everything &nbsp;else &nbsp;we&quot;, &nbsp; &quot;do &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&quot; ]</pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= words.length &lt;= 300</code></li> <li><code>1 &lt;= words[i].length &lt;= 20</code></li> <li><code>words[i]</code> consists of only English letters and symbols.</li> <li><code>1 &lt;= maxWidth &lt;= 100</code></li> <li><code>words[i].length &lt;= maxWidth</code></li> </ul>
Array; String; Simulation
C++
class Solution { public: vector<string> fullJustify(vector<string>& words, int maxWidth) { vector<string> ans; for (int i = 0, n = words.size(); i < n;) { vector<string> t = {words[i]}; int cnt = words[i].size(); ++i; while (i < n && cnt + 1 + words[i].size() <= maxWidth) { cnt += 1 + words[i].size(); t.emplace_back(words[i++]); } if (i == n || t.size() == 1) { string left = t[0]; for (int j = 1; j < t.size(); ++j) { left += " " + t[j]; } string right = string(maxWidth - left.size(), ' '); ans.emplace_back(left + right); continue; } int spaceWidth = maxWidth - (cnt - t.size() + 1); int w = spaceWidth / (t.size() - 1); int m = spaceWidth % (t.size() - 1); string row; for (int j = 0; j < t.size() - 1; ++j) { row += t[j] + string(w + (j < m ? 1 : 0), ' '); } row += t.back(); ans.emplace_back(row); } return ans; } };
68
Text Justification
Hard
<p>Given an array of strings <code>words</code> and a width <code>maxWidth</code>, format the text such that each line has exactly <code>maxWidth</code> characters and is fully (left and right) justified.</p> <p>You should pack your words in a greedy approach; that is, pack as many words as you can in each line. Pad extra spaces <code>&#39; &#39;</code> when necessary so that each line has exactly <code>maxWidth</code> characters.</p> <p>Extra spaces between words should be distributed as evenly as possible. If the number of spaces on a line does not divide evenly between words, the empty slots on the left will be assigned more spaces than the slots on the right.</p> <p>For the last line of text, it should be left-justified, and no extra space is inserted between words.</p> <p><strong>Note:</strong></p> <ul> <li>A word is defined as a character sequence consisting of non-space characters only.</li> <li>Each word&#39;s length is guaranteed to be greater than <code>0</code> and not exceed <code>maxWidth</code>.</li> <li>The input array <code>words</code> contains at least one word.</li> </ul> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> words = [&quot;This&quot;, &quot;is&quot;, &quot;an&quot;, &quot;example&quot;, &quot;of&quot;, &quot;text&quot;, &quot;justification.&quot;], maxWidth = 16 <strong>Output:</strong> [ &nbsp; &nbsp;&quot;This &nbsp; &nbsp;is &nbsp; &nbsp;an&quot;, &nbsp; &nbsp;&quot;example &nbsp;of text&quot;, &nbsp; &nbsp;&quot;justification. &nbsp;&quot; ]</pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> words = [&quot;What&quot;,&quot;must&quot;,&quot;be&quot;,&quot;acknowledgment&quot;,&quot;shall&quot;,&quot;be&quot;], maxWidth = 16 <strong>Output:</strong> [ &nbsp; &quot;What &nbsp; must &nbsp; be&quot;, &nbsp; &quot;acknowledgment &nbsp;&quot;, &nbsp; &quot;shall be &nbsp; &nbsp; &nbsp; &nbsp;&quot; ] <strong>Explanation:</strong> Note that the last line is &quot;shall be &quot; instead of &quot;shall be&quot;, because the last line must be left-justified instead of fully-justified. Note that the second line is also left-justified because it contains only one word.</pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> words = [&quot;Science&quot;,&quot;is&quot;,&quot;what&quot;,&quot;we&quot;,&quot;understand&quot;,&quot;well&quot;,&quot;enough&quot;,&quot;to&quot;,&quot;explain&quot;,&quot;to&quot;,&quot;a&quot;,&quot;computer.&quot;,&quot;Art&quot;,&quot;is&quot;,&quot;everything&quot;,&quot;else&quot;,&quot;we&quot;,&quot;do&quot;], maxWidth = 20 <strong>Output:</strong> [ &nbsp; &quot;Science &nbsp;is &nbsp;what we&quot;, &quot;understand &nbsp; &nbsp; &nbsp;well&quot;, &nbsp; &quot;enough to explain to&quot;, &nbsp; &quot;a &nbsp;computer. &nbsp;Art is&quot;, &nbsp; &quot;everything &nbsp;else &nbsp;we&quot;, &nbsp; &quot;do &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&quot; ]</pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= words.length &lt;= 300</code></li> <li><code>1 &lt;= words[i].length &lt;= 20</code></li> <li><code>words[i]</code> consists of only English letters and symbols.</li> <li><code>1 &lt;= maxWidth &lt;= 100</code></li> <li><code>words[i].length &lt;= maxWidth</code></li> </ul>
Array; String; Simulation
C#
public class Solution { public IList<string> FullJustify(string[] words, int maxWidth) { var ans = new List<string>(); for (int i = 0, n = words.Length; i < n;) { var t = new List<string>(); t.Add(words[i]); int cnt = words[i].Length; ++i; while (i < n && cnt + 1 + words[i].Length <= maxWidth) { t.Add(words[i]); cnt += 1 + words[i].Length; ++i; } if (i == n || t.Count == 1) { string left = string.Join(" ", t); string right = new string(' ', maxWidth - left.Length); ans.Add(left + right); continue; } int spaceWidth = maxWidth - (cnt - t.Count + 1); int w = spaceWidth / (t.Count - 1); int m = spaceWidth % (t.Count - 1); var row = new StringBuilder(); for (int j = 0; j < t.Count - 1; ++j) { row.Append(t[j]); row.Append(new string(' ', w + (j < m ? 1 : 0))); } row.Append(t[t.Count - 1]); ans.Add(row.ToString()); } return ans; } }
68
Text Justification
Hard
<p>Given an array of strings <code>words</code> and a width <code>maxWidth</code>, format the text such that each line has exactly <code>maxWidth</code> characters and is fully (left and right) justified.</p> <p>You should pack your words in a greedy approach; that is, pack as many words as you can in each line. Pad extra spaces <code>&#39; &#39;</code> when necessary so that each line has exactly <code>maxWidth</code> characters.</p> <p>Extra spaces between words should be distributed as evenly as possible. If the number of spaces on a line does not divide evenly between words, the empty slots on the left will be assigned more spaces than the slots on the right.</p> <p>For the last line of text, it should be left-justified, and no extra space is inserted between words.</p> <p><strong>Note:</strong></p> <ul> <li>A word is defined as a character sequence consisting of non-space characters only.</li> <li>Each word&#39;s length is guaranteed to be greater than <code>0</code> and not exceed <code>maxWidth</code>.</li> <li>The input array <code>words</code> contains at least one word.</li> </ul> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> words = [&quot;This&quot;, &quot;is&quot;, &quot;an&quot;, &quot;example&quot;, &quot;of&quot;, &quot;text&quot;, &quot;justification.&quot;], maxWidth = 16 <strong>Output:</strong> [ &nbsp; &nbsp;&quot;This &nbsp; &nbsp;is &nbsp; &nbsp;an&quot;, &nbsp; &nbsp;&quot;example &nbsp;of text&quot;, &nbsp; &nbsp;&quot;justification. &nbsp;&quot; ]</pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> words = [&quot;What&quot;,&quot;must&quot;,&quot;be&quot;,&quot;acknowledgment&quot;,&quot;shall&quot;,&quot;be&quot;], maxWidth = 16 <strong>Output:</strong> [ &nbsp; &quot;What &nbsp; must &nbsp; be&quot;, &nbsp; &quot;acknowledgment &nbsp;&quot;, &nbsp; &quot;shall be &nbsp; &nbsp; &nbsp; &nbsp;&quot; ] <strong>Explanation:</strong> Note that the last line is &quot;shall be &quot; instead of &quot;shall be&quot;, because the last line must be left-justified instead of fully-justified. Note that the second line is also left-justified because it contains only one word.</pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> words = [&quot;Science&quot;,&quot;is&quot;,&quot;what&quot;,&quot;we&quot;,&quot;understand&quot;,&quot;well&quot;,&quot;enough&quot;,&quot;to&quot;,&quot;explain&quot;,&quot;to&quot;,&quot;a&quot;,&quot;computer.&quot;,&quot;Art&quot;,&quot;is&quot;,&quot;everything&quot;,&quot;else&quot;,&quot;we&quot;,&quot;do&quot;], maxWidth = 20 <strong>Output:</strong> [ &nbsp; &quot;Science &nbsp;is &nbsp;what we&quot;, &quot;understand &nbsp; &nbsp; &nbsp;well&quot;, &nbsp; &quot;enough to explain to&quot;, &nbsp; &quot;a &nbsp;computer. &nbsp;Art is&quot;, &nbsp; &quot;everything &nbsp;else &nbsp;we&quot;, &nbsp; &quot;do &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&quot; ]</pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= words.length &lt;= 300</code></li> <li><code>1 &lt;= words[i].length &lt;= 20</code></li> <li><code>words[i]</code> consists of only English letters and symbols.</li> <li><code>1 &lt;= maxWidth &lt;= 100</code></li> <li><code>words[i].length &lt;= maxWidth</code></li> </ul>
Array; String; Simulation
Go
func fullJustify(words []string, maxWidth int) (ans []string) { for i, n := 0, len(words); i < n; { t := []string{words[i]} cnt := len(words[i]) i++ for i < n && cnt+1+len(words[i]) <= maxWidth { cnt += 1 + len(words[i]) t = append(t, words[i]) i++ } if i == n || len(t) == 1 { left := strings.Join(t, " ") right := strings.Repeat(" ", maxWidth-len(left)) ans = append(ans, left+right) continue } spaceWidth := maxWidth - (cnt - len(t) + 1) w := spaceWidth / (len(t) - 1) m := spaceWidth % (len(t) - 1) row := strings.Builder{} for j, s := range t[:len(t)-1] { row.WriteString(s) row.WriteString(strings.Repeat(" ", w)) if j < m { row.WriteString(" ") } } row.WriteString(t[len(t)-1]) ans = append(ans, row.String()) } return }
68
Text Justification
Hard
<p>Given an array of strings <code>words</code> and a width <code>maxWidth</code>, format the text such that each line has exactly <code>maxWidth</code> characters and is fully (left and right) justified.</p> <p>You should pack your words in a greedy approach; that is, pack as many words as you can in each line. Pad extra spaces <code>&#39; &#39;</code> when necessary so that each line has exactly <code>maxWidth</code> characters.</p> <p>Extra spaces between words should be distributed as evenly as possible. If the number of spaces on a line does not divide evenly between words, the empty slots on the left will be assigned more spaces than the slots on the right.</p> <p>For the last line of text, it should be left-justified, and no extra space is inserted between words.</p> <p><strong>Note:</strong></p> <ul> <li>A word is defined as a character sequence consisting of non-space characters only.</li> <li>Each word&#39;s length is guaranteed to be greater than <code>0</code> and not exceed <code>maxWidth</code>.</li> <li>The input array <code>words</code> contains at least one word.</li> </ul> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> words = [&quot;This&quot;, &quot;is&quot;, &quot;an&quot;, &quot;example&quot;, &quot;of&quot;, &quot;text&quot;, &quot;justification.&quot;], maxWidth = 16 <strong>Output:</strong> [ &nbsp; &nbsp;&quot;This &nbsp; &nbsp;is &nbsp; &nbsp;an&quot;, &nbsp; &nbsp;&quot;example &nbsp;of text&quot;, &nbsp; &nbsp;&quot;justification. &nbsp;&quot; ]</pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> words = [&quot;What&quot;,&quot;must&quot;,&quot;be&quot;,&quot;acknowledgment&quot;,&quot;shall&quot;,&quot;be&quot;], maxWidth = 16 <strong>Output:</strong> [ &nbsp; &quot;What &nbsp; must &nbsp; be&quot;, &nbsp; &quot;acknowledgment &nbsp;&quot;, &nbsp; &quot;shall be &nbsp; &nbsp; &nbsp; &nbsp;&quot; ] <strong>Explanation:</strong> Note that the last line is &quot;shall be &quot; instead of &quot;shall be&quot;, because the last line must be left-justified instead of fully-justified. Note that the second line is also left-justified because it contains only one word.</pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> words = [&quot;Science&quot;,&quot;is&quot;,&quot;what&quot;,&quot;we&quot;,&quot;understand&quot;,&quot;well&quot;,&quot;enough&quot;,&quot;to&quot;,&quot;explain&quot;,&quot;to&quot;,&quot;a&quot;,&quot;computer.&quot;,&quot;Art&quot;,&quot;is&quot;,&quot;everything&quot;,&quot;else&quot;,&quot;we&quot;,&quot;do&quot;], maxWidth = 20 <strong>Output:</strong> [ &nbsp; &quot;Science &nbsp;is &nbsp;what we&quot;, &quot;understand &nbsp; &nbsp; &nbsp;well&quot;, &nbsp; &quot;enough to explain to&quot;, &nbsp; &quot;a &nbsp;computer. &nbsp;Art is&quot;, &nbsp; &quot;everything &nbsp;else &nbsp;we&quot;, &nbsp; &quot;do &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&quot; ]</pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= words.length &lt;= 300</code></li> <li><code>1 &lt;= words[i].length &lt;= 20</code></li> <li><code>words[i]</code> consists of only English letters and symbols.</li> <li><code>1 &lt;= maxWidth &lt;= 100</code></li> <li><code>words[i].length &lt;= maxWidth</code></li> </ul>
Array; String; Simulation
Java
class Solution { public List<String> fullJustify(String[] words, int maxWidth) { List<String> ans = new ArrayList<>(); for (int i = 0, n = words.length; i < n;) { List<String> t = new ArrayList<>(); t.add(words[i]); int cnt = words[i].length(); ++i; while (i < n && cnt + 1 + words[i].length() <= maxWidth) { cnt += 1 + words[i].length(); t.add(words[i++]); } if (i == n || t.size() == 1) { String left = String.join(" ", t); String right = " ".repeat(maxWidth - left.length()); ans.add(left + right); continue; } int spaceWidth = maxWidth - (cnt - t.size() + 1); int w = spaceWidth / (t.size() - 1); int m = spaceWidth % (t.size() - 1); StringBuilder row = new StringBuilder(); for (int j = 0; j < t.size() - 1; ++j) { row.append(t.get(j)); row.append(" ".repeat(w + (j < m ? 1 : 0))); } row.append(t.get(t.size() - 1)); ans.add(row.toString()); } return ans; } }
68
Text Justification
Hard
<p>Given an array of strings <code>words</code> and a width <code>maxWidth</code>, format the text such that each line has exactly <code>maxWidth</code> characters and is fully (left and right) justified.</p> <p>You should pack your words in a greedy approach; that is, pack as many words as you can in each line. Pad extra spaces <code>&#39; &#39;</code> when necessary so that each line has exactly <code>maxWidth</code> characters.</p> <p>Extra spaces between words should be distributed as evenly as possible. If the number of spaces on a line does not divide evenly between words, the empty slots on the left will be assigned more spaces than the slots on the right.</p> <p>For the last line of text, it should be left-justified, and no extra space is inserted between words.</p> <p><strong>Note:</strong></p> <ul> <li>A word is defined as a character sequence consisting of non-space characters only.</li> <li>Each word&#39;s length is guaranteed to be greater than <code>0</code> and not exceed <code>maxWidth</code>.</li> <li>The input array <code>words</code> contains at least one word.</li> </ul> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> words = [&quot;This&quot;, &quot;is&quot;, &quot;an&quot;, &quot;example&quot;, &quot;of&quot;, &quot;text&quot;, &quot;justification.&quot;], maxWidth = 16 <strong>Output:</strong> [ &nbsp; &nbsp;&quot;This &nbsp; &nbsp;is &nbsp; &nbsp;an&quot;, &nbsp; &nbsp;&quot;example &nbsp;of text&quot;, &nbsp; &nbsp;&quot;justification. &nbsp;&quot; ]</pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> words = [&quot;What&quot;,&quot;must&quot;,&quot;be&quot;,&quot;acknowledgment&quot;,&quot;shall&quot;,&quot;be&quot;], maxWidth = 16 <strong>Output:</strong> [ &nbsp; &quot;What &nbsp; must &nbsp; be&quot;, &nbsp; &quot;acknowledgment &nbsp;&quot;, &nbsp; &quot;shall be &nbsp; &nbsp; &nbsp; &nbsp;&quot; ] <strong>Explanation:</strong> Note that the last line is &quot;shall be &quot; instead of &quot;shall be&quot;, because the last line must be left-justified instead of fully-justified. Note that the second line is also left-justified because it contains only one word.</pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> words = [&quot;Science&quot;,&quot;is&quot;,&quot;what&quot;,&quot;we&quot;,&quot;understand&quot;,&quot;well&quot;,&quot;enough&quot;,&quot;to&quot;,&quot;explain&quot;,&quot;to&quot;,&quot;a&quot;,&quot;computer.&quot;,&quot;Art&quot;,&quot;is&quot;,&quot;everything&quot;,&quot;else&quot;,&quot;we&quot;,&quot;do&quot;], maxWidth = 20 <strong>Output:</strong> [ &nbsp; &quot;Science &nbsp;is &nbsp;what we&quot;, &quot;understand &nbsp; &nbsp; &nbsp;well&quot;, &nbsp; &quot;enough to explain to&quot;, &nbsp; &quot;a &nbsp;computer. &nbsp;Art is&quot;, &nbsp; &quot;everything &nbsp;else &nbsp;we&quot;, &nbsp; &quot;do &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&quot; ]</pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= words.length &lt;= 300</code></li> <li><code>1 &lt;= words[i].length &lt;= 20</code></li> <li><code>words[i]</code> consists of only English letters and symbols.</li> <li><code>1 &lt;= maxWidth &lt;= 100</code></li> <li><code>words[i].length &lt;= maxWidth</code></li> </ul>
Array; String; Simulation
Python
class Solution: def fullJustify(self, words: List[str], maxWidth: int) -> List[str]: ans = [] i, n = 0, len(words) while i < n: t = [] cnt = len(words[i]) t.append(words[i]) i += 1 while i < n and cnt + 1 + len(words[i]) <= maxWidth: cnt += 1 + len(words[i]) t.append(words[i]) i += 1 if i == n or len(t) == 1: left = ' '.join(t) right = ' ' * (maxWidth - len(left)) ans.append(left + right) continue space_width = maxWidth - (cnt - len(t) + 1) w, m = divmod(space_width, len(t) - 1) row = [] for j, s in enumerate(t[:-1]): row.append(s) row.append(' ' * (w + (1 if j < m else 0))) row.append(t[-1]) ans.append(''.join(row)) return ans
68
Text Justification
Hard
<p>Given an array of strings <code>words</code> and a width <code>maxWidth</code>, format the text such that each line has exactly <code>maxWidth</code> characters and is fully (left and right) justified.</p> <p>You should pack your words in a greedy approach; that is, pack as many words as you can in each line. Pad extra spaces <code>&#39; &#39;</code> when necessary so that each line has exactly <code>maxWidth</code> characters.</p> <p>Extra spaces between words should be distributed as evenly as possible. If the number of spaces on a line does not divide evenly between words, the empty slots on the left will be assigned more spaces than the slots on the right.</p> <p>For the last line of text, it should be left-justified, and no extra space is inserted between words.</p> <p><strong>Note:</strong></p> <ul> <li>A word is defined as a character sequence consisting of non-space characters only.</li> <li>Each word&#39;s length is guaranteed to be greater than <code>0</code> and not exceed <code>maxWidth</code>.</li> <li>The input array <code>words</code> contains at least one word.</li> </ul> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> words = [&quot;This&quot;, &quot;is&quot;, &quot;an&quot;, &quot;example&quot;, &quot;of&quot;, &quot;text&quot;, &quot;justification.&quot;], maxWidth = 16 <strong>Output:</strong> [ &nbsp; &nbsp;&quot;This &nbsp; &nbsp;is &nbsp; &nbsp;an&quot;, &nbsp; &nbsp;&quot;example &nbsp;of text&quot;, &nbsp; &nbsp;&quot;justification. &nbsp;&quot; ]</pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> words = [&quot;What&quot;,&quot;must&quot;,&quot;be&quot;,&quot;acknowledgment&quot;,&quot;shall&quot;,&quot;be&quot;], maxWidth = 16 <strong>Output:</strong> [ &nbsp; &quot;What &nbsp; must &nbsp; be&quot;, &nbsp; &quot;acknowledgment &nbsp;&quot;, &nbsp; &quot;shall be &nbsp; &nbsp; &nbsp; &nbsp;&quot; ] <strong>Explanation:</strong> Note that the last line is &quot;shall be &quot; instead of &quot;shall be&quot;, because the last line must be left-justified instead of fully-justified. Note that the second line is also left-justified because it contains only one word.</pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> words = [&quot;Science&quot;,&quot;is&quot;,&quot;what&quot;,&quot;we&quot;,&quot;understand&quot;,&quot;well&quot;,&quot;enough&quot;,&quot;to&quot;,&quot;explain&quot;,&quot;to&quot;,&quot;a&quot;,&quot;computer.&quot;,&quot;Art&quot;,&quot;is&quot;,&quot;everything&quot;,&quot;else&quot;,&quot;we&quot;,&quot;do&quot;], maxWidth = 20 <strong>Output:</strong> [ &nbsp; &quot;Science &nbsp;is &nbsp;what we&quot;, &quot;understand &nbsp; &nbsp; &nbsp;well&quot;, &nbsp; &quot;enough to explain to&quot;, &nbsp; &quot;a &nbsp;computer. &nbsp;Art is&quot;, &nbsp; &quot;everything &nbsp;else &nbsp;we&quot;, &nbsp; &quot;do &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&quot; ]</pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= words.length &lt;= 300</code></li> <li><code>1 &lt;= words[i].length &lt;= 20</code></li> <li><code>words[i]</code> consists of only English letters and symbols.</li> <li><code>1 &lt;= maxWidth &lt;= 100</code></li> <li><code>words[i].length &lt;= maxWidth</code></li> </ul>
Array; String; Simulation
TypeScript
function fullJustify(words: string[], maxWidth: number): string[] { const ans: string[] = []; for (let i = 0, n = words.length; i < n; ) { const t: string[] = [words[i]]; let cnt = words[i++].length; while (i < n && cnt + 1 + words[i].length <= maxWidth) { t.push(words[i]); cnt += 1 + words[i++].length; } if (i === n || t.length === 1) { const left: string = t.join(' '); const right: string = ' '.repeat(maxWidth - left.length); ans.push(left + right); continue; } const spaceWidth: number = maxWidth - (cnt - t.length + 1); const w: number = Math.floor(spaceWidth / (t.length - 1)); const m: number = spaceWidth % (t.length - 1); const row: string[] = []; for (let j = 0; j < t.length - 1; ++j) { row.push(t[j]); row.push(' '.repeat(w + (j < m ? 1 : 0))); } row.push(t[t.length - 1]); ans.push(row.join('')); } return ans; }
69
Sqrt(x)
Easy
<p>Given a non-negative integer <code>x</code>, return <em>the square root of </em><code>x</code><em> rounded down to the nearest integer</em>. The returned integer should be <strong>non-negative</strong> as well.</p> <p>You <strong>must not use</strong> any built-in exponent function or operator.</p> <ul> <li>For example, do not use <code>pow(x, 0.5)</code> in c++ or <code>x ** 0.5</code> in python.</li> </ul> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> x = 4 <strong>Output:</strong> 2 <strong>Explanation:</strong> The square root of 4 is 2, so we return 2. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> x = 8 <strong>Output:</strong> 2 <strong>Explanation:</strong> The square root of 8 is 2.82842..., and since we round it down to the nearest integer, 2 is returned. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>0 &lt;= x &lt;= 2<sup>31</sup> - 1</code></li> </ul>
Math; Binary Search
C++
class Solution { public: int mySqrt(int x) { int l = 0, r = x; while (l < r) { int mid = (l + r + 1ll) >> 1; if (mid > x / mid) { r = mid - 1; } else { l = mid; } } return l; } };
69
Sqrt(x)
Easy
<p>Given a non-negative integer <code>x</code>, return <em>the square root of </em><code>x</code><em> rounded down to the nearest integer</em>. The returned integer should be <strong>non-negative</strong> as well.</p> <p>You <strong>must not use</strong> any built-in exponent function or operator.</p> <ul> <li>For example, do not use <code>pow(x, 0.5)</code> in c++ or <code>x ** 0.5</code> in python.</li> </ul> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> x = 4 <strong>Output:</strong> 2 <strong>Explanation:</strong> The square root of 4 is 2, so we return 2. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> x = 8 <strong>Output:</strong> 2 <strong>Explanation:</strong> The square root of 8 is 2.82842..., and since we round it down to the nearest integer, 2 is returned. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>0 &lt;= x &lt;= 2<sup>31</sup> - 1</code></li> </ul>
Math; Binary Search
C#
public class Solution { public int MySqrt(int x) { int l = 0, r = x; while (l < r) { int mid = (l + r + 1) >>> 1; if (mid > x / mid) { r = mid - 1; } else { l = mid; } } return l; } }
69
Sqrt(x)
Easy
<p>Given a non-negative integer <code>x</code>, return <em>the square root of </em><code>x</code><em> rounded down to the nearest integer</em>. The returned integer should be <strong>non-negative</strong> as well.</p> <p>You <strong>must not use</strong> any built-in exponent function or operator.</p> <ul> <li>For example, do not use <code>pow(x, 0.5)</code> in c++ or <code>x ** 0.5</code> in python.</li> </ul> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> x = 4 <strong>Output:</strong> 2 <strong>Explanation:</strong> The square root of 4 is 2, so we return 2. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> x = 8 <strong>Output:</strong> 2 <strong>Explanation:</strong> The square root of 8 is 2.82842..., and since we round it down to the nearest integer, 2 is returned. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>0 &lt;= x &lt;= 2<sup>31</sup> - 1</code></li> </ul>
Math; Binary Search
Go
func mySqrt(x int) int { return sort.Search(x+1, func(i int) bool { return i*i > x }) - 1 }
69
Sqrt(x)
Easy
<p>Given a non-negative integer <code>x</code>, return <em>the square root of </em><code>x</code><em> rounded down to the nearest integer</em>. The returned integer should be <strong>non-negative</strong> as well.</p> <p>You <strong>must not use</strong> any built-in exponent function or operator.</p> <ul> <li>For example, do not use <code>pow(x, 0.5)</code> in c++ or <code>x ** 0.5</code> in python.</li> </ul> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> x = 4 <strong>Output:</strong> 2 <strong>Explanation:</strong> The square root of 4 is 2, so we return 2. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> x = 8 <strong>Output:</strong> 2 <strong>Explanation:</strong> The square root of 8 is 2.82842..., and since we round it down to the nearest integer, 2 is returned. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>0 &lt;= x &lt;= 2<sup>31</sup> - 1</code></li> </ul>
Math; Binary Search
Java
class Solution { public int mySqrt(int x) { int l = 0, r = x; while (l < r) { int mid = (l + r + 1) >>> 1; if (mid > x / mid) { r = mid - 1; } else { l = mid; } } return l; } }
69
Sqrt(x)
Easy
<p>Given a non-negative integer <code>x</code>, return <em>the square root of </em><code>x</code><em> rounded down to the nearest integer</em>. The returned integer should be <strong>non-negative</strong> as well.</p> <p>You <strong>must not use</strong> any built-in exponent function or operator.</p> <ul> <li>For example, do not use <code>pow(x, 0.5)</code> in c++ or <code>x ** 0.5</code> in python.</li> </ul> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> x = 4 <strong>Output:</strong> 2 <strong>Explanation:</strong> The square root of 4 is 2, so we return 2. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> x = 8 <strong>Output:</strong> 2 <strong>Explanation:</strong> The square root of 8 is 2.82842..., and since we round it down to the nearest integer, 2 is returned. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>0 &lt;= x &lt;= 2<sup>31</sup> - 1</code></li> </ul>
Math; Binary Search
JavaScript
/** * @param {number} x * @return {number} */ var mySqrt = function (x) { let [l, r] = [0, x]; while (l < r) { const mid = (l + r + 1) >> 1; if (mid > x / mid) { r = mid - 1; } else { l = mid; } } return l; };
69
Sqrt(x)
Easy
<p>Given a non-negative integer <code>x</code>, return <em>the square root of </em><code>x</code><em> rounded down to the nearest integer</em>. The returned integer should be <strong>non-negative</strong> as well.</p> <p>You <strong>must not use</strong> any built-in exponent function or operator.</p> <ul> <li>For example, do not use <code>pow(x, 0.5)</code> in c++ or <code>x ** 0.5</code> in python.</li> </ul> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> x = 4 <strong>Output:</strong> 2 <strong>Explanation:</strong> The square root of 4 is 2, so we return 2. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> x = 8 <strong>Output:</strong> 2 <strong>Explanation:</strong> The square root of 8 is 2.82842..., and since we round it down to the nearest integer, 2 is returned. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>0 &lt;= x &lt;= 2<sup>31</sup> - 1</code></li> </ul>
Math; Binary Search
Python
class Solution: def mySqrt(self, x: int) -> int: l, r = 0, x while l < r: mid = (l + r + 1) >> 1 if mid > x // mid: r = mid - 1 else: l = mid return l
69
Sqrt(x)
Easy
<p>Given a non-negative integer <code>x</code>, return <em>the square root of </em><code>x</code><em> rounded down to the nearest integer</em>. The returned integer should be <strong>non-negative</strong> as well.</p> <p>You <strong>must not use</strong> any built-in exponent function or operator.</p> <ul> <li>For example, do not use <code>pow(x, 0.5)</code> in c++ or <code>x ** 0.5</code> in python.</li> </ul> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> x = 4 <strong>Output:</strong> 2 <strong>Explanation:</strong> The square root of 4 is 2, so we return 2. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> x = 8 <strong>Output:</strong> 2 <strong>Explanation:</strong> The square root of 8 is 2.82842..., and since we round it down to the nearest integer, 2 is returned. </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>0 &lt;= x &lt;= 2<sup>31</sup> - 1</code></li> </ul>
Math; Binary Search
Rust
impl Solution { pub fn my_sqrt(x: i32) -> i32 { let mut l = 0; let mut r = x; while l < r { let mid = (l + r + 1) / 2; if mid > x / mid { r = mid - 1; } else { l = mid; } } l } }
70
Climbing Stairs
Easy
<p>You are climbing a staircase. It takes <code>n</code> steps to reach the top.</p> <p>Each time you can either climb <code>1</code> or <code>2</code> steps. In how many distinct ways can you climb to the top?</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> n = 2 <strong>Output:</strong> 2 <strong>Explanation:</strong> There are two ways to climb to the top. 1. 1 step + 1 step 2. 2 steps </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> n = 3 <strong>Output:</strong> 3 <strong>Explanation:</strong> There are three ways to climb to the top. 1. 1 step + 1 step + 1 step 2. 1 step + 2 steps 3. 2 steps + 1 step </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 45</code></li> </ul>
Memoization; Math; Dynamic Programming
C++
class Solution { public: int climbStairs(int n) { int a = 0, b = 1; for (int i = 0; i < n; ++i) { int c = a + b; a = b; b = c; } return b; } };
70
Climbing Stairs
Easy
<p>You are climbing a staircase. It takes <code>n</code> steps to reach the top.</p> <p>Each time you can either climb <code>1</code> or <code>2</code> steps. In how many distinct ways can you climb to the top?</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> n = 2 <strong>Output:</strong> 2 <strong>Explanation:</strong> There are two ways to climb to the top. 1. 1 step + 1 step 2. 2 steps </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> n = 3 <strong>Output:</strong> 3 <strong>Explanation:</strong> There are three ways to climb to the top. 1. 1 step + 1 step + 1 step 2. 1 step + 2 steps 3. 2 steps + 1 step </pre> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 45</code></li> </ul>
Memoization; Math; Dynamic Programming
Go
func climbStairs(n int) int { a, b := 0, 1 for i := 0; i < n; i++ { a, b = b, a+b } return b }